Sabtu, 23 Juni 2012
FILE SHARING AND PROGRAM
.
Report to the Chairman and Ranking
Minority Member, Committee on
Government Reform, House of
Representatives
United States General Accounting Office
GAO
February 2003 FILE-SHARING
PROGRAMS
Peer-to-Peer Networks
Provide Ready Access
to Child Pornography
GAO-03-351
Child pornography is easily found and downloaded from peer-to-peer
networks. In one search using 12 keywords known to be associated with
child pornography on the Internet, GAO identified 1,286 titles and file names,
determining that 543 (about 42 percent) were associated with child
pornography images. Of the remaining, 34 percent were classified as adult
pornography and 24 percent as nonpornographic. In another search using
three keywords, a Customs analyst downloaded 341 images, of which 149
(about 44 percent) contained child pornography (see the figure below).
These results are in accord with increased reports of child pornography on
peer-to-peer networks; since it began tracking these in 2001, the National
Center for Missing and Exploited Children has seen a fourfold increase—
from 156 in 2001 to 757 in 2002. Although the numbers are as yet small by
comparison to those for other sources (26,759 reports of child pornography
on Web sites in 2002), the increase is significant.
Juvenile users of peer-to-peer networks are at significant risk of inadvertent
exposure to pornography, including child pornography. Searches on
innocuous keywords likely to be used by juveniles (such as names of
cartoon characters or celebrities) produced a high proportion of
pornographic images: in our searches, the retrieved images included adult
pornography (34 percent), cartoon pornography (14 percent), child erotica
(7 percent), and child pornography (1 percent).
While federal law enforcement agencies—including the FBI, Justice’s Child
Exploitation and Obscenity Section, and Customs—are devoting resources
to combating child exploitation and child pornography in general, these
agencies do not track the resources dedicated to specific technologies used
to access and download child pornography on the Internet. Therefore, GAO
was unable to quantify the resources devoted to investigating cases on peerto-
peer networks. According to law enforcement officials, however, as tips
concerning child pornography on peer-to-peer networks escalate, law
enforcement resources are increasingly being focused on this area.
Classification of Images Downloaded through Peer-to-Peer File-Sharing Program
FILE-SHARING PROGRAMS
Peer-to-Peer Networks Provide Ready
Access to Child Pornography
www.gao.gov/cgi-bin/getrpt?GAO-03-351.
To view the full report, including the scope
and methodology, click on the link above.
For more information, contact Linda Koontz at
(202) 512-6240 or koontzl@gao.gov.
Highlights of GAO-03-351, a report to the
Chairman and Ranking Minority Member,
Committee on Government Reform,
House of Representatives
February 2003
The availability of child
pornography has dramatically
increased in recent years as it has
migrated from printed material to
the World Wide Web, becoming
accessible through Web sites, chat
rooms, newsgroups, and now the
increasingly popular peer-to-peer
file-sharing programs. These
programs enable direct
communication between users,
allowing users to access each
other’s files and share digital
music, images, and video.
GAO was requested to determine
the ease of access to child
pornography on peer-to-peer
networks; the risk of inadvertent
exposure of juvenile users of peerto-
peer networks to pornography,
including child pornography; and
the extent of federal law
enforcement resources available
for combating child pornography
on peer-to-peer networks.
Because child pornography cannot
be accessed legally other than by
law enforcement agencies, GAO
worked with the Customs Cyber-
Smuggling Center in performing
searches: Customs downloaded
and analyzed image files, and GAO
performed analyses based on
keywords and file names only.
In commenting on a draft of this
report, the Department of Justice
agreed with the report’s findings
and provided additional
information.
Page i GAO-03-351 File-Sharing Programs
Letter 1
Results in Brief 2
Background 3
Peer-to-Peer Applications Provide Easy Access to Child
Pornography 11
Juvenile Users of Peer-to-Peer Applications May Be Inadvertently
Exposed to Pornography 14
Federal Law Enforcement Agencies Are Beginning to Focus
Resources on Child Pornography on Peer-to-Peer Networks 15
Conclusions 17
Agency Comments and Our Evaluation 17
Appendix I Objectives, Scope, and Methodology 19
Appendix II Description of File Sharing and Peer-to-Peer
Networks 21
Appendix III Comments from the Department of Justice 26
Glossary 29
Tables
Table 1: Internet Technologies Providing Access to Child
Pornography 7
Table 2: Organizations and Agencies Involved with Peer-to-Peer
Child Pornography Efforts 9
Table 3: NCMEC CyberTipline Referrals to Law Enforcement
Agencies, Fiscal Years 1998–2002 14
Figures
Figure 1: Classification of 1,286 Titles and File Names of Images
Identified in KaZaA Search 12
Figure 2: Classification of 341 Images Downloaded through KaZaA 13
Contents
Page ii GAO-03-351 File-Sharing Programs
Figure 3: Classification of 177 Images of a Popular Singer, Child
Actors, and a Cartoon Character Downloaded through
KaZaA 15
Figure 4: Peer-to-Peer Models 22
Figure 5: Topology of a Gnutella Network 25
Abbreviations
CEOS Child Exploitation and Obscenity Section
FBI Federal Bureau of Investigation
IRC Internet Relay Chat
MP3 Moving Pictures Experts Group (MPEG) MPEG-1 Audio
Layer-3
NCMEC National Center for Missing and Exploited Children
NCVIP National Child Victim Identification Program
NRC National Research Council
P2P peer to peer
URL Uniform Resource Locator
VNS virtual name space
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Page 1 GAO-03-351 File-Sharing Programs
February 20, 2003
The Honorable Tom Davis
Chairman
The Honorable Henry A. Waxman
Ranking Minority Member
Committee on Government Reform
House of Representatives
The availability of child pornography has dramatically increased in recent
years as it has migrated from magazines, photographs, and videos to the
World Wide Web. The Internet’s wide range of information search and
retrieval technologies, which make it possible to quickly find a vast array
of information, also make it easy to access, disseminate, and trade
pornographic images and videos, including child pornography.
Increasingly, child pornography is accessible through Web sites, chat
rooms, newsgroups, and the increasingly popular peer-to-peer technology,
which allows direct communication between computer users, so that they
can access and share each other’s files (including images, video, and
software).
As requested, our objectives were to determine (1) the ease of access to
child pornography on peer-to-peer networks; (2) the risk of inadvertent
exposure of juvenile users of peer-to-peer networks to pornography,
including child pornography; and (3) the extent of federal law enforcement
resources available for combating child pornography on peer-to-peer
networks.
To address the first two objectives, we were assisted by the U.S. Customs
CyberSmuggling Center in using a peer-to-peer application to search for
image files matching keywords that were intended to identify pornography
and child pornography images or that might accidentally identify
pornographic images. The resulting files were downloaded, saved,
analyzed, and classified by a U.S. Customs CyberSmuggling agent.1 To
determine what federal law enforcement resources are allocated to
combating child pornography on peer-to-peer networks, we analyzed
1Because child pornography cannot be accessed legally other than by law enforcement
agencies, we relied on Customs to download and analyze image files. We performed
analyses based on titles and file names only.
United States General Accounting Office
Washington, DC 20548
Page 2 GAO-03-351 File-Sharing Programs
resource allocation data at the Federal Bureau of Investigation and the
Child Exploitation and Obscenity Section within the Department of
Justice, and at the U.S. Customs Service and U.S. Secret Service within the
Department of the Treasury. We also received documentation about what
resources were being allocated to combat child pornography from the
National Center for Missing and Exploited Children, a federally funded
nonprofit organization that serves as a national resource center for
information related to crimes against children.
Appendix I contains a more detailed discussion of our objectives, scope,
and methodology. Appendix II provides more information on the
characteristics and use of peer-to-peer file-sharing programs.
Child pornography is easily accessed and downloaded from peer-to-peer
networks. Using KaZaA, a popular peer-to-peer file-sharing program, we
used 12 keywords known to be associated with child pornography on the
Internet to search for child pornography image files. We identified 1,286
items, each with a title and file name, determining that 543 (about 42
percent) were associated with child pornography images. Of the
remaining, 34 percent were classified as adult pornography and 24 percent
as nonpornographic. In another search using three keywords, the Customs
CyberSmuggling Center also used KaZaA to search for and download child
pornography image files.2 This search identified 341 image files, of which
149 (about 44 percent) were classified as child pornography.3 The
remaining images were classified as child erotica4 (13 percent), adult
pornography (29 percent), or other (nonpornographic) images (14
percent). These results are consistent with observations of the National
Center for Missing and Exploited Children, which has stated that peer-topeer
technology is increasingly popular for the dissemination of child
pornography. Although peer-to-peer networks are currently not the most
prominent source for child pornography, law enforcement agencies have
noted a significant increase in their use for this purpose. Since 2001, when
the center began to track peer-to-peer child pornography, peer-to-peer
2Other popular peer-to-peer applications include Gnutella, BearShare, LimeWire, and
Morpheus.
3Customs downloaded and analyzed image files for us because child pornography can be
legally accessed only by law enforcement agencies.
4Erotic images of children that do not depict sexually explicit conduct.
Results in Brief
Page 3 GAO-03-351 File-Sharing Programs
reports have increased more than fourfold—from 156 in 2001 to 757 in
2002.
When searching and downloading images on peer-to-peer networks,
juvenile users face a significant risk of inadvertent exposure to
pornography, including child pornography. Searches on innocuous
keywords likely to be used by juveniles produce images of which a high
proportion are pornographic: in our searches, the retrieved images
included adult pornography (34 percent), cartoon pornography5 (14
percent), child erotica (7 percent), and child pornography (1 percent).
We were unable to determine the precise extent of federal law
enforcement resources available for combating child pornography on
peer-to-peer networks. While several law enforcement agencies—
including the Federal Bureau of Investigation, Justice’s Child Exploitation
and Obscenity Section, and Customs—devote resources to combating
child exploitation and child pornography in general, they do not track the
resources dedicated to specific technologies used to access and download
child pornography on the Internet. Therefore, we were unable to quantify
the resources devoted to investigations of peer-to-peer networking. Law
enforcement officials told us, however, that as they receive larger numbers
of tips concerning child pornography on peer-to-peer networks, they are
focusing more law enforcement resources in this area.
In commenting on a draft of this report, the Department of Justice agreed
with the report’s findings and provided some additional information;
Justice’s comments are reprinted in appendix III. We also received
technical comments from the U.S. Secret Service and the U.S. Customs
Service. Their comments have been incorporated in the report as
appropriate.
Federal statutes provide for civil and criminal penalties for the production,
advertising, possession, receipt, distribution, and sale of child
pornography.6 Of particular relevance to this report, the child pornography
statutes prohibit the use of any means of interstate or foreign commerce
(which will typically include the use of an interactive computer service) to
sell, advertise, distribute, receive, or possess child pornography.
5Images of cartoon characters depicting sexually explicit conduct.
6See chapter 110 of Title 18, U.S. Code.
Background
Page 4 GAO-03-351 File-Sharing Programs
Additionally, federal obscenity statutes prohibit the use of any means of
interstate or foreign commerce or an interactive computer service to
import, transport, or distribute obscene material or to transfer obscene
material to persons under the age of 16.7
Child pornography is defined by statute as the visual depiction of a
minor—a person under 18 years of age—engaged in sexually explicit
conduct.8 By contrast, for material to be defined as obscene depends on
whether an average person, applying contemporary community standards,
would interpret the work—including images—to appeal to the prurient
interest and to be patently offensive, and whether a reasonable person
would find the material lacks serious literary, artistic, political, or
scientific value.9
In addition to making it a crime to transport, receive, sell, distribute,
advertise, or possess child pornography in interstate or foreign commerce,
federal child pornography statutes prohibit, among other things, the use of
a minor in producing pornography, and they provide for criminal and civil
forfeiture of real and personal property used in making child pornography
and of the profits of child pornography.10 Child pornography, which is
intrinsically related to the sexual abuse of children, is unprotected by the
First Amendment.11 Nor does the First Amendment protect the production,
distribution, or transfer of obscene material.12
7See chapter 71 of Title 18, U.S. Code.
8See 18 U.S.C. § 2256(8).
9See Miller v. California, 413 U.S. 15 (1973). In Miller, the Supreme Court created a threepart
test to determine whether a work is obscene. The Miller test, as interpreted by
subsequent Supreme Court jurisprudence, asks (a) whether an average person applying
contemporary community standards would find that the material, taken as a whole, appeals
to the prurient interest; (b) whether an average person applying contemporary community
standards would find that the material depicts proscribed behavior in a patently offensive
manner; and (c) whether a reasonable person would find that the material, taken as a
whole, lacks serious literary, artistic, political, or scientific value. As the Miller test is
unrelated to child pornography, it does not account for the government’s compelling
interest in protecting children from sexual exploitation.
10See chapter 110, Title 18, U.S. Code.
11See New York v. Ferber, 458 U.S. 747 (1982).
12See Roth v. United States, 354 U.S. 476 (1957). In contrast, the private possession of
obscenity in one’s home is protected by the First Amendment. See Stanley v. Georgia,
394 U.S. 557 (1969).
Page 5 GAO-03-351 File-Sharing Programs
In enacting the Child Pornography Prevention Act of 1996,13 Congress
sought to expand the federal prohibition against child pornography from
images that involve actual children to sexually explicit images that only
appear to depict minors but were produced without using any real
children. The act defines child pornography as “any visual depiction,
including any photograph, film, video, picture, or computer or computergenerated
image or picture” that “is, or appears to be, of a minor engaging
in sexually explicit conduct” or is “advertised, promoted, presented,
described, or distributed in such a manner that conveys the impression
that the material is or contains a visual depiction of a minor engaging in
sexually explicit conduct.” Last year, the Supreme Court struck down this
legislative attempt to ban “virtual” child pornography14 in Ashcroft v. The
Free Speech Coalition, ruling that the expansion of the act to material that
did not involve and thus harm actual children in its creation is an
unconstitutional violation of free speech rights. According to government
officials, this ruling may increase the difficulty faced by law enforcement
agencies in prosecuting those who produce and possess child
pornography. Since the government must establish that the digital images
of children engaged in sexual acts are those of real children, it may be
difficult to prosecute cases in which the defendants claim that the images
in question are of “virtual” children.
13Section 121, P.L. 104-208, 110 Stat. 3009-26.
14According to the Justice Department, rapidly advancing technology has raised the
possibility of creating images of child pornography without the use of a real child (“virtual”
child pornography). Totally virtual creations would be both time intensive and, for now,
prohibitively costly to produce. However, the technology has led to a ready defense (the
“virtual” porn defense) against prosecution under laws that are limited to sexually explicit
depictions of actual minors. Because the technology does exist today to alter images in a
manner that disguises the identity of the real child or makes the image seem computergenerated,
it encourages producers and distributors of child pornography to alter
depictions of actual children in slight ways to make them not only unidentifiable, but also
appear as if they were virtual creations—and thereby attempt to defeat prosecution. In
contrast to the weighty task of creating an entire image out of whole cloth, it is not difficult
or expensive to use readily available technology to disguise depictions of real children to
make them unidentifiable or to make them appear computer generated.
Page 6 GAO-03-351 File-Sharing Programs
Historically, pornography, including child pornography, tended to be
found mainly in photographs, magazines, and videos.15 The arrival and the
rapid expansion of the Internet and its technologies, the increased
availability of broadband Internet services, advances in digital imaging
technologies, and the availability of powerful digital graphic programs
have brought about major changes in both the volume and the nature of
available child pornography. The proliferation of child pornography on the
Internet is prompting wide concern. According to a recent survey, over 90
percent of Americans say they are concerned about child pornography on
the Internet, and 50 percent of Americans cite child pornography as the
single most heinous crime that takes place on line.16
According to experts, pornographers have traditionally exploited—and
sometimes pioneered—emerging communication technologies—from the
dial-in bulletin board systems of the 1970s to the World Wide Web—to
access, trade, and distribute pornography, including child pornography.17
Today, child pornography is available through virtually every Internet
technology (see table 1).
15John Carr, Theme Paper on Child Pornography for the 2nd World Congress on
Commercial Sexual Exploitation of Children, NCH Children’s Charities, Children &
Technology Unit (Yokohama, 2001).
(http://www.ecpat.net/eng/Ecpat_inter/projects/monitoring/wc2/yokohama_theme_child_p
ornography.pdf)
16Susannah Fox and Oliver Lewis, Fear of Online Crime: Americans Support FBI
Interception of Criminal Suspects’ Email and New Laws to Protect Online Privacy, Pew
Internet & American Life Project (Apr. 2, 2001).
(http://www.pewInternet.org/reports/pdfs/PIP_Fear_of_crime.pdf)
17Frederick E. Allen, “When Sex Drives Technological Innovation and Why It Has to,”
American Heritage Magazine, vol. 51, no. 5 (September 2000), p. 19.
(http://www.plannedparenthood.org/education/updatearch.html)
Allen notes that pornographers have driven the development of some of the Internet
technologies, including the development of systems used to verify on-line financial
transactions and that of digital watermarking technology to prevent the unauthorized use
of on-line images.
The Internet Has Emerged
as the Principal Tool for
Exchanging Child
Pornography
Page 7 GAO-03-351 File-Sharing Programs
Table 1: Internet Technologies Providing Access to Child Pornography
Technology Characteristics
World Wide Web Web sites provide on-line access to text and multimedia
materials identified and accessed through the uniform
resource locator (URL).
Usenet A distributed electronic bulletin system, Usenet offers over
80,000 newsgroups, with many newsgroups dedicated to
sharing of digital images.
Peer-to-peer file-sharing
programs
Internet applications operating over peer-to-peer networks
enable direct communication between users. Used largely
for sharing of digital music, images, and video, peer-to-peer
applications include BearShare, Gnutella, LimeWire, and
KaZaA. KaZaA is the most popular, with over 3 million
KaZaA users sharing files at any time.
E-mail E-mail allows the transmission of messages over a network
or the Internet. Users can send E-mail to a single recipient or
broadcast it to multiple users. E-mail supports the delivery of
attached files, including image files.
Instant messaging Instant messaging is not a dial-up system like the telephone;
it requires that both parties be on line at the same time.
AOL’s Instant Messenger and Microsoft’s MSN Messenger
and Internet Relay Chat are the major instant messaging
services. Users may exchange files, including image files.
Chat and Internet Relay
Chat
Chat technologies allow computer conferencing using the
keyboard over the Internet between two or more people.
Source: GAO.
Among the principal channels for the distribution of child pornography are
commercial Web sites, Usenet newsgroups, and peer-to-peer networks.18
Web sites. According to recent estimates, there are about 400,000
commercial pornography Web sites worldwide,19 with some of the sites
selling pornographic images of children. The profitability and the
worldwide reach of the child pornography trade was recently
demonstrated by an international child pornography ring that included a
Texas-based firm providing credit card billing and password access
services for one Russian and two Indonesian child pornography Web sites.
18According to Department of Justice officials, other forums and technologies are used to
disseminate pornography on the Internet. These include Web portal communities such as
Yahoo! Groups and MSN Groups, as well as file servers operating on Internet Relay Chat
channels.
19Dick Thornburgh and Herbert S. Lin, editors, Youth, Pornography, and The Internet,
National Academy Press (Washington, D.C.: 2002).
(http://www.nap.edu/html/youth_internet/)
Page 8 GAO-03-351 File-Sharing Programs
According to the U.S. Postal Inspection Service, the ring grossed as much
as $1.4 million in just 1 month selling child pornography to paying
customers.
Usenet. Usenet newsgroups are also providing access to pornography,
with several of the image-oriented newsgroups being focused on child
erotica and child pornography. These newsgroups are frequently used by
commercial pornographers who post “free” images to advertise adult and
child pornography available for a fee from their Web sites. The increase in
the availability of child pornography in Usenet newsgroups represents a
change from the mid-1990’s, when a 1995–96 study of 9,800 randomly
selected images taken from 32 Usenet newsgroups found that only a small
fraction of posted images contained child pornography themes.20
Peer-to-peer networks. Although peer-to-peer file-sharing programs are
largely known for the extensive sharing of copyrighted digital music,21 they
are emerging as a conduit for the sharing of child pornography images and
videos. A recent study by congressional staff found that one use of filesharing
programs is to exchange pornographic materials, such as adult
videos.22 The study found that a single search for the term “porn” using a
similar file-sharing program yielded over 25,000 files, more than 10,000 of
which were video files appearing to contain pornographic images. In
another study, focused on the availability of pornographic video files on
peer-to-peer sharing networks, a sample of 507 pornographic video files
retrieved with a file-sharing program included about 3.7 percent child
pornography videos.23
20Michael D. Mehta, “Pornography in Usenet: A Study of 9,800 Randomly Selected Images,”
CyberPsychology and Behavior, vol. 4, no. 6 (2001).
21According to the Yankee Group, a technology research and consulting firm, Internet users
aged 14 and older downloaded 5.16 billion audio files in the United States via unlicensed
file-sharing services in 2001.
22Minority Staff, Children’s Access to Pornography through Internet File-Sharing
Programs, Special Investigations Division, Committee on Government Reform, U.S. House
of Representatives (July 27, 2001).
(http://www.house.gov/reform/min/pdfs/pdf_inves/pdf_pornog_rep.pdf)
23Michael D. Mehta, Don Best, and Nancy Poon, “Peer-to-Peer Sharing on the Internet: An
Analysis of How Gnutella Networks Are Used to Distribute Pornographic Material,”
Canadian Journal of Law and Technology, vol. 1, no. 1 (January 2002).
(http://cjlt.dal.ca/vol1_no1/articles/01_01_MeBePo_gnutella.pdf)
Page 9 GAO-03-351 File-Sharing Programs
Table 2 shows the key national organizations and agencies that are
currently involved in efforts to combat child pornography on peer-to-peer
networks.
Table 2: Organizations and Agencies Involved with Peer-to-Peer Child Pornography
Efforts
Agency Unit Focus
Nonprofit
National Center for
Missing and
Exploited Children
Exploited Child
Unit
Works with the Customs Service, Postal
Service, and the FBI to analyze and
investigate child pornography leads.
Federal entities
Department of
Justice
Federal Bureau of
Investigationa
Proactively investigates crimes against
children. Operates a national “innocent
Images Initiative” to combat Internet-related
sexual exploitation of children.
Criminal Division,
Child Exploitation
and Obscenity
Section
Is a specialized group of attorneys who,
among other things, prosecute those who
possess, manufacture, or distribute child
pornography. Its High Tech Investigative Unit
actively conducts on-line investigations to
identify distributors of obscenity and child
pornography.
Department of the
Treasury
U.S. Customs
Service
CyberSmuggling
Centera
Conducts international child pornography
investigations as part of its mission to
investigate international criminal activity
conducted on or facilitated by the Internet.
U.S. Secret
Servicea
Provides forensic and technical assistance in
matters involving missing and sexually
exploited children.
Source: GAO.
aAgency has staff assigned to NCMEC.
The National Center for Missing and Exploited Children (NCMEC), a
federally funded nonprofit organization, serves as a national resource
center for information related to crimes against children. Its mission is to
find missing children and prevent child victimization. The center’s
Exploited Child Unit operates the CyberTipline, which receives child
pornography tips provided by the public; its CyberTipline II also receives
tips from Internet service providers. The Exploited Child Unit investigates
and processes tips to determine if the images in question constitute a
violation of child pornography laws. The CyberTipline provides
investigative leads to the Federal Bureau of Investigation (FBI), U.S.
Customs, the Postal Inspection Service, and state and local law
enforcement agencies. The FBI and the U.S. Customs also investigate
leads from Internet service providers via the Exploited Child Unit’s
Several Agencies Have
Law Enforcement
Responsibilities Regarding
Child Pornography on
Peer-to-Peer Networks
Page 10 GAO-03-351 File-Sharing Programs
CyberTipline II. The FBI, Customs Service, Postal Inspection Service, and
Secret Service have staff24 assigned directly to NCMEC as analysts.
Two organizations in the Department of Justice have responsibilities
regarding child pornography: the FBI and the Justice Criminal Division’s
Child Exploitation and Obscenity Section (CEOS).25
• The FBI investigates various crimes against children, including federal
child pornography crimes involving interstate or foreign commerce. It
deals with violations of child pornography laws related to the production
of child pornography; selling or buying children for use in child
pornography; and the transportation, shipment, or distribution of child
pornography by any means, including by computer.
• CEOS prosecutes child sex offenses and trafficking in women and children
for sexual exploitation. Its mission includes prosecution of individuals
who possess, manufacture, produce, or distribute child pornography; use
the Internet to lure children to engage in prohibited sexual conduct; or
traffic in women and children interstate or internationally to engage in
sexually explicit conduct.
Two organizations in the Department of the Treasury have responsibilities
regarding child pornography: the Customs Service26 and the Secret Service.
• The Customs Service targets illegal importation and trafficking in child
pornography and is the country’s front line of defense in combating child
pornography distributed through various channels, including the Internet.
Customs is involved in cases with international links, focusing on
pornography that enters the United States from foreign countries. The
Customs CyberSmuggling Center has the lead in the investigation of
international and domestic criminal activities conducted on or facilitated
by the Internet, including the sharing and distribution of child
pornography on peer-to-peer networks. Customs maintains a reporting
24In commenting on our report, the Secret Service noted that its staff assigned to NCMEC
include analysts and an agent.
25Two additional Justice agencies are involved in combating child pornography: the U.S.
Attorneys Offices and the Office of Juvenile Justice and Delinquency Prevention. The 94
U.S. Attorneys Offices can prosecute federal child exploitation-related cases; the Office of
Juvenile Justice and Delinquency Prevention funds the Internet Crimes Against Children
Task Force Program, which encourages multijurisdictional and multiagency responses to
crimes against children involving the Internet.
26Under the Homeland Security Act of 2002, the Customs Service is to become part of the
new Department of Homeland Security.
Page 11 GAO-03-351 File-Sharing Programs
link with NCMEC, and it acts on tips received via the CyberTipline from
callers reporting instances of child pornography on Web sites, Usenet
newsgroups, chat rooms, or the computers of users of peer-to-peer
networks. The center also investigates leads from Internet service
providers via the Exploited Child Unit’s CyberTipline II.
• The U.S. Secret Service does not investigate child pornography cases on
peer-to-peer networks; however, it does provide forensic and technical
support to NCMEC, as well as to state and local agencies involved in cases
of missing and exploited children.
In November 2002, we reported that federal agencies are effectively
coordinating their efforts to combat child pornography, and we
recommended that the Attorney General designate the Postal Inspection
Service and Secret Service as agencies that should receive reports and tips
of child pornography under the Protection of Children from Sexual
Predators Act of 1998 in addition to the FBI and Customs.27
The Department of Justice, while agreeing with our finding that federal
agencies have mechanisms in place to coordinate their efforts, did not
fully support our conclusion and recommendation that federal
coordination efforts would be further enhanced if the Postal Inspection
Service and the Secret Service were provided direct access to tips
reported to NCMEC by remote computing service and electronic
communication service providers. Justice said that the FBI and Customs,
the agencies that currently have direct access, can and do share these tips
with the Secret Service and the Postal Inspection Service, as appropriate,
and Justice believes that this coordination has been effective. Justice
questioned whether coordination would be further enhanced by having the
Secret Service and the Postal Inspection Service designated to receive
access to these tips directly from NCMEC; however, Justice said that it is
studying this issue as it finalizes regulations implementing the statute.
Child pornography is easily shared and accessed through peer-to-peer filesharing
programs. Our analysis of 1,286 titles and file names identified
through KaZaA searches on 12 keywords28 showed that 543 (about 42
percent) of the images had titles and file names associated with child
27U.S. General Accounting Office, Combating Child Pornography: Federal Agencies
Coordinate Law Enforcement Efforts, but an Opportunity Exists for Further
Enhancements, GAO-03-272 (Washington, D.C.: Nov. 29, 2002).
28The 12 keywords were provided by the Cybersmuggling Center as examples known to be
associated with child pornography on the Internet.
Peer-to-Peer
Applications Provide
Easy Access to Child
Pornography
Page 12 GAO-03-351 File-Sharing Programs
pornography images.29 Of the remaining files, 34 percent were classified as
adult pornography, and 24 percent as nonpornographic (see fig. 1). No
files were downloaded for this analysis.
Figure 1: Classification of 1,286 Titles and File Names of Images Identified in KaZaA
Search
The ease of access to child pornography files was further documented by
retrieval and analysis of image files, performed on our behalf by the
Customs CyberSmuggling Center. Using 3 of the 12 keywords that we used
to document the availability of child pornography files, a CyberSmuggling
Center analyst used KaZaA to search, identify, and download 305 files,
including files containing multiple images and duplicates. The analyst was
able to download 341 images from the 305 files identified through the
KaZaA search.
The CyberSmuggling Center analysis of the 341 downloaded images
showed that 149 (about 44 percent) of the downloaded images contained
child pornography (see fig. 2). The center classified the remaining images
as child erotica (13 percent), adult pornography (29 percent), or
nonpornographic (14 percent).
29We categorized a file as child pornography if one keyword indicating a minor and one
word with a sexual connotation occurred in either the title or file name. Files with sexual
connotation in title or name but without age indicators were classified as adult
pornography.
Page 13 GAO-03-351 File-Sharing Programs
Figure 2: Classification of 341 Images Downloaded through KaZaA
Note: GAO analysis of data provided by the Customs CyberSmuggling Center.
These results are consistent with the observations of NCMEC, which has
stated that peer-to-peer technology is increasingly popular for the
dissemination of child pornography. However, it is not the most prominent
source for child pornography. As shown in table 3, since 1998, most of the
child pornography referred by the public to the CyberTipline was found on
Internet Web sites. Since 1998, the center has received over 76,000 reports
of child pornography, of which 77 percent concerned Web sites, and only
1 percent concerned peer-to-peer networks. Web site referrals have grown
from about 1,400 in 1998 to over 26,000 in 2002—or about a nineteenfold
increase. NCMEC did not track peer-to-peer referrals until 2001. In 2002,
peer-to-peer referrals increased more than fourfold, from 156 to 757,
reflecting the increased popularity of file-sharing programs.
Page 14 GAO-03-351 File-Sharing Programs
Table 3: NCMEC CyberTipline Referrals to Law Enforcement Agencies, Fiscal Years
1998–2002
Number of tips
Technology 1998 1999 2000 2001 2002
Web sites 1,393 3,830 10,629 18,052 26,759
E-mail 117 165 120 1,128 6,245
Peer-to-peer — — — 156 757
Usenet newsgroups & bulletin
boards 531 987 731 990 993
Unknown 90 258 260 430 612
Chat rooms 155 256 176 125 234
Instant Messaging 27 47 50 80 53
File Transfer Protocol 25 26 58 64 23
Total 2,338 5,569 12,024 21,025 35,676
Source: Exploited Child Unit, National Center for Missing and Exploited Children.
Juvenile users of peer-to-peer networks face a significant risk of
inadvertent exposure to pornography when searching and downloading
images. In a search using innocuous keywords likely to be used by
juveniles searching peer-to-peer networks (such as names of popular
singers, actors, and cartoon characters), almost half of the images
downloaded were classified as adult or cartoon pornography. Juvenile
users may also be inadvertently exposed to child pornography through
such searches, but the risk of such exposure is smaller than that of
exposure to pornography in general.
To document the risk of inadvertent exposure of juvenile users to
pornography, the Customs CyberSmuggling Center performed KaZaA
searches using innocuous keywords that would likely be used by juveniles.
The center image searches used three keywords representing the names of
a popular female singer, child actors, and a cartoon character. A center
analyst performed the search, retrieval, and analysis of the images, each of
which was classified into one of five categories: child pornography, child
erotica, adult pornography, cartoon pornography, or nonpornographic.
The searches produced 157 files, some of which were duplicates. The
analyst was able to download 177 images from the 157 files identified
through the search.
As shown in figure 3, our analysis of the CyberSmuggling Center’s
classification of the 177 downloaded images determined that 61 images
contained adult pornography (34 percent), 24 images consisted of cartoon
Juvenile Users of
Peer-to-Peer
Applications May Be
Inadvertently
Exposed to
Pornography
Page 15 GAO-03-351 File-Sharing Programs
pornography (14 percent), 13 images contained child erotica (7 percent),
and 2 images (1 percent) contained child pornography. The remaining 77
images were classified as nonpornographic.
Figure 3: Classification of 177 Images of a Popular Singer, Child Actors, and a
Cartoon Character Downloaded through KaZaA
Note: GAO analysis of data provided by the Customs CyberSmuggling Center.
Because law enforcement agencies do not track the resources dedicated to
specific technologies used to access and download child pornography on
the Internet, we were unable to quantify the resources devoted to
investigations concerning peer-to-peer networks. These agencies
(including the FBI, CEOS, and Customs) do devote significant resources to
combating child exploitation and child pornography in general. Law
enforcement officials told us, however, that as tips concerning child
pornography on the peer-to-peer networks increase, they are beginning to
focus more law enforcement resources on this issue.
In fiscal year 2002, the key organizations involved in combating child
pornography on peer-to-peer networks reported the following levels of
funding:
Federal Law
Enforcement
Agencies Are
Beginning to Focus
Resources on Child
Pornography on Peerto-
Peer Networks
Page 16 GAO-03-351 File-Sharing Programs
• NCMEC received about $12 million for its congressionally mandated role
as the national resource center and clearinghouse. NCMEC also received
about $10 million for law enforcement training and about $3.3 million for
the Exploited Child Unit and the promotion of its CyberTipline. From the
appropriated amounts, NCMEC allocated $916,000 to combat child
pornography and referred 913 tips concerning peer-to-peer networks to
law enforcement agencies.
• The FBI allocated $38.2 million and 228 agents and support personnel to
combat child pornography through its Innocent Images unit. Since fiscal
year 1996, the Innocent Image National Initiative opened 7,067 cases,
obtained 1,811 indictments, performed 1,886 arrests, and secured 1,850
convictions or pretrial diversions in child pornography cases. According to
FBI officials, they are aware of the use of peer-to-peer networks to
disseminate child pornography and have efforts under way to work with
some of the peer-to-peer companies to solicit their cooperation in dealing
with this issue.
• CEOS allocated $4.38 million and 28 personnel to combat child
exploitation and obscenity offenses. It has recently launched an effort, the
High Tech Investigative Unit, dealing with investigating any Internet
medium that distributes child pornography, including peer-to-peer
networks.
• Customs allocated $15.6 million and over 144,000 hours to combating child
exploitation and obscenity offenses.30 The CyberSmuggling Center is
beginning to actively monitor the file sharing of child pornography on
peer-to-peer networks and is devoting one half-time investigator to this
effort. As of December 16, 2002, the center has sent 21 peer-to-peer
investigative leads to the field offices for follow-up action. Four of these
leads have search warrants pending, two have been referred to local law
enforcement, and five have been referred to foreign law enforcement
agencies.
In addition, to facilitate the identification of the victims of child
pornographers, the CyberSmuggling Center is devoting resources to the
National Child Victim Identification Program, a consolidated information
system containing seized images that is designed to allow law enforcement
officials to quickly identify and combat the current abuse of children
associated with the production of child pornography. The system’s
database is being populated with all known and unique child pornographic
images obtained from national and international law enforcement sources
30Customs is unable to separate the staff hours devoted or funds obligated to combating
child pornography from those dedicated to combating child exploitation in general.
Page 17 GAO-03-351 File-Sharing Programs
and from CyberTipline reports filed with NCMEC. It will initially hold over
100,000 images that have been collected by federal law enforcement
agencies from various sources, including old child pornography
magazines.31 According to Customs officials, this information will help,
among other things, to determine whether actual children were used to
produce child pornography images by matching them with images of
children from magazines published before modern imaging technology
was invented. Such evidence can be used to counter the assertion that
only virtual children appear in certain images.
The system is housed at the Customs CyberSmuggling Center and is to be
accessed remotely in “read only” format by the FBI, CEOS, the U.S. Postal
Inspection Service, and NCMEC. An initial version of the system was
deployed at the Customs CyberSmuggling Center in September 2002; the
system became operational in January 2003.32
It is easy to access and download child pornography on peer-to-peer
networks. Juvenile users of peer-to-peer networks also face a significant
risk of inadvertent exposure to pornography, including child pornography.
We were unable to determine the extent of federal law enforcement
resources available for combating child pornography on peer-to-peer
networks; the key law enforcement agencies devote resources to
combating child exploitation and child pornography in general, but they do
not track the resources dedicated to peer-to-peer technologies in
particular.
The Assistant Attorney General, Criminal Division, Department of Justice,
provided written comments on a draft of this report, which are reprinted
in appendix III. The Department of Justice agreed with the report’s
findings, provided additional information on the mission and capabilities
of the High Tech Investigative Unit (part of its Criminal Division’s Child
Exploitation and Obscenity Section), and offered comments on the
description and purpose of Customs’ National Child Victim Identification
31According to federal law enforcement agencies, most of the child pornography published
before 1970 has been digitized and made widely available on the Internet.
32One million dollars has already been spent on the system, with an additional $5 million
needed for additional hardware, the expansion of the image database, and access for all
involved agencies. The 10-year lifecycle cost of the system is estimated to be $23 million.
Conclusions
Agency Comments
and Our Evaluation
Page 18 GAO-03-351 File-Sharing Programs
Program. In response, we have revised our report to add these
clarifications. We also received written technical comments from the
Department of Justice, which we have incorporated as appropriate.
We received written technical comments from the Assistant Director,
Office of Inspection, U.S. Secret Service, and from the Acting Director,
Office of Planning, U.S. Customs Service. Their comments have been
incorporated in the report as appropriate.
As agreed with your office, unless you publicly announce the contents of
this report earlier, we plan no further distribution until 30 days from the
report date. At that time, we will send copies of this report to the
Chairmen and Ranking Minority Members of other Senate and House
committees and subcommittees that have jurisdiction and oversight
responsibility for the Departments of Justice and the Treasury. We will
also send copies to the Attorney General and to the Secretary of the
Treasury. Copies will be made available to others on request. In addition,
this report will be available at no charge on the GAO Web site at
http://www.gao.gov.
If you have any questions concerning this report, please call me at (202)
512-6240 or Mirko J. Dolak, Assistant Director, at (202) 512-6362. We can
be also reached by E-mail at koontzl@gao.gov and dolakm@gao.gov,
respectively. Key contributors to this report were Barbara S. Collier,
James M. Lager, Neelaxi V. Lakhmani, James R. Sweetman, Jr., and Jessie
Thomas.
Linda D. Koontz
Director, Information Management Issues
Appendix I:
Page 19 GAO-03-351 File-Sharing Programs
Our objectives were to
• determine the ease of access to child pornography on peer-to-peer
networks,
• assess the risk of inadvertent exposure of juvenile users of peer-to-peer
networks to pornography, including child pornography, and
• determine the extent of federal law enforcement resources available for
combating child pornography on peer-to-peer networks.
To determine the availability of child pornography on peer-to-peer
networks, we used a popular peer-to-peer application—KaZaA—to search
for and identify image files that appear to be child pornography. Our
analysts used keywords provided by the Customs CyberSmuggling Center.
These keywords were intended to identify pornographic images; examples
of the keywords include preteen, underage, and incest.
Once the names and titles of image files were gathered, we classified and
analyzed them based on file names and keywords. Each file was classified
as child pornography, adult pornography, or nonpornographic. For a file to
be considered possible child pornography, the title, file name, or both had
to include at least one word with a sexual connotation and an age-related
keyword indicating that the subject is a minor. Files depicting adult
pornography included any file that had words of a sexual nature in the title
or file name. No files were downloaded for this analysis.
To determine the ease of access, we used three keywords from the initial
list to perform another search. The resulting files were downloaded, saved,
and analyzed by a Customs agent. Because child pornography cannot be
accessed legally other than by law enforcement agencies, we relied on
Customs to download and analyze files. Our own analyses were based on
keywords and file names only. The Customs agent classified each of the
downloaded files into one of four categories: child pornography, child
erotica, adult pornography, or nonpornographic. The user with the largest
number of shared files that appeared to be child pornography was also
identified, and the shared folder was captured. The titles and names of
files in the user’s shared directory were then analyzed and classified by a
GAO analyst using the same classification criteria used in original analysis.
To assess the risk of inadvertent exposure of juvenile users of peer-to-peer
networks to pornography, a CyberSmuggling Center analyst conducted
another search using three keywords that are names of popular celebrities
and a cartoon character. The Customs analyst performed the search,
retrieval, and analysis of the images. Each of the images downloaded was
Appendix I: OApbpjeecntdiviexs I,: SOcbojpeec,t iavneds , Scope,
Methodology
Appendix I: Objectives, Scope, and
Methodology
Page 20 GAO-03-351 File-Sharing Programs
classified into one of five categories: adult pornography, child
pornography, child erotica, cartoon pornography, or nonpornographic.
To determine what federal law enforcement resources were allocated to
combating child pornography on peer-to-peer networks, we obtained
resource allocation data and interviewed officials at the U.S. Customs
Service, the Department of Justice’s Child Exploitation and Obscenity
Section, and the Federal Bureau of Investigation. We also received
information about what resources were being allocated to combat child
pornography from the U.S. Secret Service and the National Center for
Missing and Exploited Children.
We performed our work between July and October 2002 at the U.S. Secret
Service in Baltimore, Maryland, and the U.S. Customs Service, Customs
CyberSmuggling Center, in Fairfax, Virginia, under the Department of the
Treasury; and at the Child Exploitation and Obscenity Section and the
Federal Bureau of Investigation, under the Department of Justice, in
Washington, D.C. We also worked with the National Center for Missing
and Exploited Children in Alexandria, Virginia. Our work was conducted
in accordance with generally accepted government auditing standards.
Appendix II: Description of File Sharing and
Peer-to-Peer Networks
Page 21 GAO-03-351 File-Sharing Programs
Peer-to-peer file-sharing programs represent a major change in the way
Internet users find and exchange information. Under the traditional
Internet client/server model, the access to information and services is
accomplished by the interaction between users (clients) and servers—
usually Web sites or portals. A client is defined as a requester of services,
and a server is defined as the provider of services. Unlike the traditional
model, the peer-to-peer model enables consenting users—or peers—to
directly interact and share information with each other without the
intervention of a server. A common characteristic of peer-to-peer
programs is that they build virtual networks with their own mechanisms
for routing message traffic.1
The ability of peer-to-peer networks to provide services and connect users
directly has resulted in a large number2 of powerful applications built
around this model.3 These range from the SETI@home network (where
users share the computing power of their computers to search for
extraterrestrial life) to the popular KaZaA file-sharing program (used to
share music and other files).
As shown in figure 4,4 there are two main models of peer-to-peer networks:
(1) the centralized model, based on a central server or broker that directs
traffic between individual registered users, and (2) the decentralized
1Matei Ripenau, Ian Foster, and Adriana Iamnitchi, “Mapping the Gnutella Network:
Properties of Large Scale Peer-to-Peer Systems and Implication for System Design,” IEEE
Internet Computing, vol. 6, no. 1 (January–February 2002).
(people.cs.uchicago.edu/~matei/PAPERS/ic.pdf)
2Zeropaid.com, a file-sharing portal, lists 88 different peer-to-peer file-sharing programs
available for download. (http://www.zeropaid.com/php/filesharing.php)
3Geoffrey Fox and Shrideep Pallickara, “Peer-to-Peer Interactions in Web Brokering
Systems,” Ubiquity, vol. 3, no. 15 (May 28–June 3, 2002) (published by Association of
Computer Machinery). (http://www.acm.org/ubiquity/views/g_fox_2.html)
4Illustration adapted by Lt. Col. Mark Bontrager from original by Bob Knighten, “Peer-to-
Peer Computing,” briefing to Peer-to-Peer Working Groups (August 24, 2000), in Mark D.
Bontrager, Peering into the Future: Peer-to-Peer Technology as a Model for Distributed
Joint Battlespace Intelligence Dissemination and Operational Tasking, Thesis, School of
Advanced Airpower Studies, Air University, Maxwell Air Force Base, Alabama (June 2001).
Appendix II: Description of File Sharing and
Peer-to-Peer Networks
Appendix II: Description of File Sharing and
Peer-to-Peer Networks
Page 22 GAO-03-351 File-Sharing Programs
model, based on the Gnutella5 network, in which individuals find and
interact directly with each other.
Figure 4: Peer-to-Peer Models
Note: Adapted from Mark Bontrager’s adaptation of original by Bob Knighten.
As shown in figure 4, the centralized model relies on a central
server/broker to maintain directories of shared files stored on the
respective computers of the registered users of the peer-to-peer network.
When Bob submits a request for a particular file, the server/broker creates
a list of files matching the search request by checking the request with its
database of files belonging to registered users currently connected to the
network. The broker then displays that list to Bob, who can then select the
desired file from the list and open a direct link with Alice’s computer,
which currently has the file. The download of the actual file takes place
directly from Alice to Bob.
5According to LimeWire LLC, the developer of a popular file-sharing program, Gnutella was
originally designed by Nullsoft, a subsidiary of America Online. The development of the
Gnutella protocol was halted by AOL management shortly after the protocol was made
available to the public. Using downloads, programmers reverse-engineered the software
and created their own Gnutella software packages.
(http://www.limewire.com/index.jsp/p2p)
Appendix II: Description of File Sharing and
Peer-to-Peer Networks
Page 23 GAO-03-351 File-Sharing Programs
The broker model was used by Napster, the original peer-to-peer network,
facilitating mass sharing of copyrighted material by combining the file
names held by thousands of users into a searchable directory that enabled
users to connect with each other and download MP3 encoded music files.
The broker model made Napster vulnerable to legal challenges6 and
eventually led to its demise in September 2002.
Although Napster was litigated out of existence and its users fragmented
among many alternative peer-to-peer services, most current-generation
peer-to-peer networks are not dependent on the server/broker that was the
central feature of the Napster service, so, according to Gartner,7 these
networks are less vulnerable to litigation from copyright owners.
In the decentralized model, no brokers keep track of users and their files.
To share files using the decentralized model, Ted starts with a networked
computer equipped with a Gnutella file-sharing program, such as KaZaA or
BearShare. Ted connects to Carol, Carol to Bob, Bob to Alice, and so on.
Once Ted’s computer has announced that it is “alive” to the various
members of the peer network, it can search the contents of the shared
directories of the peer network members. The search request is sent to all
members of the network, starting with Carol, who will each in turn send
the request to the computers to which they are connected, and so forth. If
one of the computers in the peer network (say, for example, Alice’s) has a
file that matches the request, it transmits the file information (name, size,
type, etc.) back through all the computers in the pathway towards Ted,
where a list of files matching the search request appears on Ted’s
computer through the file-sharing program. Ted will then be able to open a
connection with Alice and download the file directly from Alice’s
computer.8
One of the key features of Napster and the current generation of
decentralized peer-to-peer technologies is their use of a virtual name space
(VNS). A VNS dynamically associates user-created names with the Internet
address of whatever Internet-connected computer users happen to be
6A&M Records v. Napster, 114 F.Supp.2d 896 (N.D. Cal. 2000).
7Lydia Leong, “RIAA vs.Verizon, Implications for ISPs,” Gartner (Oct. 24, 2002).
8LimeWire, Modern Peer-to-Peer File Sharing over the Internet.
(http://www.limewire.com/index.jsp/p2p)
Appendix II: Description of File Sharing and
Peer-to-Peer Networks
Page 24 GAO-03-351 File-Sharing Programs
using when they log on.9 The VNS facilitates point-to-point interaction
between individuals, because it removes the need for users and their
computers to know the addresses and locations of other users; the VNS
can, to certain extent, preserve users’ anonymity and provide information
on whether a user is or is not connected to the Internet at a given
moment.10
The file-sharing networks that result from the use of peer-to-peer
technology are both extensive and complex. Figure 5 shows a map or
topology of a Gnutella network whose connections were mapped by a
network visualization tool.11 The map, created in December 2000, shows
1,026 nodes (computers connected to more than one computer) and 3,752
edges (computers on the edge of the network connected to a single
computer). This map is a snapshot showing a network in existence at a
given moment; these networks change constantly as users join and depart
them.
9S. Hayward and R. Batchelder, “Peer-to-Peer: Something Old, Something New,” Gartner
(Apr. 10, 2001).
10Peer-to-peer users may appear to be but are not anonymous. Law enforcement agents
may identify users’ Internet addresses during the file-sharing process and obtain, under a
court order, their identities from their Internet service providers.
11Mihajlo A. Jovanovic, Fred S. Annexstein, and Kenneth A. Berman, Scalability Issues in
Large Peer-to-Peer Networks: A Case Study of Gnutella, University of Cincinnati Technical
Report (2001). (http://www.ececs.uc.edu/~mjovanov/Research/paper.html)
Appendix II: Description of File Sharing and
Peer-to-Peer Networks
Page 25 GAO-03-351 File-Sharing Programs
Figure 5: Topology of a Gnutella Network
Appendix III: Comments from the Department of Justice
Page 26 GAO-03-351 File-Sharing Programs
Appendix III: Comments from the
Department of Justice
Appendix III: Comments from the Department of Justice
Page 27 GAO-03-351 File-Sharing Programs
Appendix III: Comments from the Department of Justice
Page 28 GAO-03-351 File-Sharing Programs
Glossary
Page 29 GAO-03-351 File-Sharing Programs
Operating at bandwidths markedly greater than that provided by telephone
networks. Broadband networks can carry digital videos or a massive
quantity of data simultaneously. In the on-line environment, the term is
often used to refer to Internet connections provided through cable or DSL
(digital subscriber line) modems.
A file-sharing program for Gnutella networks. BearShare supports the
trading of text, images, audio, video, and software files with any other user
of the network.
In the peer-to-peer environment, an intermediary computer that
coordinates and manages requests between client computers.
Images of cartoon characters engaged in sexual activity.
Internet program enabling users to communicate through short written
messages. Some of the most popular chat programs are America Online’s
Instant Messenger and the Microsoft Network Messenger. See instant
messaging.
Sexually arousing images of children that are not considered
pornographic, obscene, or offensive.
A networking model in which a collection of nodes (client computers)
request and obtain services from a server node (server computer).
A file-sharing program based on the Gnutella protocol. Gnutella enables
users to directly share files with one another. Unlike Napster, Gnutellabased
programs do not rely on a central server to find files.
Decentralized group membership and search protocol, typically used for
file sharing. Gnutella file-sharing programs build a virtual network of
participating users.
Glossary
Broadband
BearShare
Broker
Cartoon pornography
Chat
Child erotica
Client-server
Gnutella
Gnutella protocol
Glossary
Page 30 GAO-03-351 File-Sharing Programs
The standard language (HyperText Markup Language) used to display
information on the Web. It uses tags embedded in text files to encode
instructions for formatting and displaying the information.
A popular method of Internet communication that allows for an
instantaneous transmission of messages to other users who are logged into
the same instant messaging service. America Online’s Instant Messenger
and the Microsoft Network Messenger are among the most popular instant
messaging programs (see chat).
Internet chat application allowing real-time conversations to take place via
software, text commands, and channels. Unlike the Web-based IM, IRC
requires special software and knowledge of technical commands (see
chat).
Internet Protocol address. A number that uniquely identifies a computer
connected to the Internet to other computers.
A file-sharing program using a proprietary peer-to-peer protocol to share
files among users on the network. Through a distributed self-organizing
network, KaZaA requires no broker or central server like Napster.
A file-sharing program running on Gnutella networks. It is open standard
software running on an open protocol, free for the public to use.
A file-sharing application using the KaZaA peer-to-peer protocol to share
files among users on the network.
A process whereby one image is gradually transformed into a second
image.
Moving Pictures Experts Group (MPEG) MPEG-1 Audio Layer-3. A widely
used standard for compressing and transmitting music in digital format
across Internet. MP3 can compress file sizes at a ratio of about 10:1 while
preserving sound quality.
Hypertext language
(HTML)
Instant messaging (IM)
Internet relay chat (IRC)
IP address
KaZaA
LimeWire
Morpheus
Morphing
MP3
Glossary
Page 31 GAO-03-351 File-Sharing Programs
Discussion groups on Usenet, varying in topic from technical to bizarre.
There are over 80,000 newsgroups organized by major areas or domains.
The major domains are alt (any conceivable topic, including pornography);
biz (business products and services); rec (games and hobbies); comp
(computer hardware and software); sci (sciences); humanities (art and
literature); soc (culture and social issues); misc (miscellaneous, including
employment and health); and talk (debates on current issues). See Usenet.
A computer or a device that is connected to a network. Every node has a
unique network address.
A network node that may function as a client or a server. In the peer-topeer
environment, peer computers are also called servents, since they
perform tasks associated with both servers and clients.
A computer that interconnects client computers, providing them with
services and information; a component of the client-server model. A Web
server is one type of server.
Search for extraterrestrial intelligence at home. A distributed computing
project, SETI@home uses data collected by the Arecibo Telescope in
Puerto Rico. The project takes advantage of the unused computing
capacity of personal computers. As of February 2000, the project
encompassed 1.6 million participants in 224 countries.
The general structure—or map—of a network. It shows the computers and
the links between them.
A bulletin board system accessible through the Internet containing more
than 80,000 newsgroups. Originally implemented in 1979, it is now
probably the largest decentralized information utility in existence (see
newsgroups).
Having the properties of x while not being x. For example, “virtual reality”
is an artificial or simulated environment that appears to be real to the
casual observer.
Newsgroups
Node
Peer
Server
SETI@home
Topology
Usenet
Virtual
Glossary
Page 32 GAO-03-351 File-Sharing Programs
Internet addressing and naming system. In the peer-to-peer environment,
VNS dynamically associates names created by users with the IP addresses
assigned by their Internet services providers to their computers.
A worldwide client-server system for searching and retrieving information
across the Internet. Also known as WWW or the Web.
Virtual name space (VNS)
World Wide Web
(310345)
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