Request for Comments: 3675 Motorola Laboratories
Category: Informational February 2004
.sex Considered Dangerous
Status of this Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2004). All Rights Reserved.
Abstract
Periodically there are proposals to mandate the use of a special top
level name or an IP address bit to flag "adult" or "unsafe" material
or the like. This document explains why this is an ill considered
idea from the legal, philosophical, and particularly, the technical
points of view.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Background . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Legal and Philosophical Problems . . . . . . . . . . . . . . . 4
4. Technical Difficulties . . . . . . . . . . . . . . . . . . . . 6
4.1. Content Filtering Using Names. . . . . . . . . . . . . . 7
4.1.1. Linguistic Problems. . . . . . . . . . . . . . . 7
4.1.2. Explosion of Top Level Domain Names (TLDs) . . . 8
4.1.3. You Can’t Control What Names Point At You! . . . 9
4.1.4. Particular Protocol Difficulties . . . . . . . . 10
4.1.4.1. Electronic Mail (SMTP) . . . . . . . . 10
4.1.4.2. Web Access (HTTP). . . . . . . . . . . 11
4.1.4.3. News (NNTP). . . . . . . . . . . . . . 12
4.1.4.4. Internet Relay Chat (IRC). . . . . . . 13
4.2. Content Filtering Using IP Addressing. . . . . . . . . . 13
4.2.1. Hierarchical Routing . . . . . . . . . . . . . . 14
4.2.2. IP Version 4 Addresses . . . . . . . . . . . . . 15
4.2.3. IP Version 6 Addresses . . . . . . . . . . . . . 15
4.3. PICS Labels. . . . . . . . . . . . . . . . . . . . . . . 16
5. Security Considerations. . . . . . . . . . . . . . . . . . . . 17
6. Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . 17
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7.1. Normative References . . . . . . . . . . . . . . . . . . 18
7.2. Informative References . . . . . . . . . . . . . . . . . 19
8. Acknowledgement. . . . . . . . . . . . . . . . . . . . . . . . 21
9. Authors’ Addresses . . . . . . . . . . . . . . . . . . . . . . 21
10. Full Copyright Statement . . . . . . . . . . . . . . . . . . . 22
1. Introduction
Periodically there are proposals to mandate the use of a special top
level name or an IP address bit to flag "adult" or "unsafe" material
or the like. This document explains why this is an ill considered
idea from the legal, philosophical, and the technical points of view.
2. Background
The concept of a .sex, .xxx, .adult, or similar top-level domain in
which it would be mandatory to locate salacious or similar material
is periodically suggested by some politicians and commentators.
Other proposals have included a domain reserved exclusively for
material viewed as appropriate for minors, or using IP address bits
or ranges to segregate content.
In an October 1998 report accompanying the Child Online Protection
Act, the House Commerce committee said, "there are no technical
barriers to creating an adult domain, and it would be very easy to
block all websites within an adult domain". The report also said
that the committee was wary of regulating the computer industry and
that any decision by the U.S. government "will have international
consequences" [HOUSEREPORT].
British Telecom has backed adult top-level domains, saying in a 1998
letter to the U.S. Department of Commerce that it "strongly
supported" that plan. The reason: "Sexually explicit services could
then be legally required to operate with domain names in this gTLD
[that] would make it much simpler and easier to control access to
such sites..." [BT]. One of ICANN’s progenitors, the GTLD-MOU
committee, suggested a "red-light-zone" top-level domain in a
September 1997 request for comment [GTLD-MOU].
Some adult industry executives have endorsed the concept. In 1998,
Seth Warshavsky, president of the Internet Entertainment Group, told
the U.S. Senate Commerce committee that he would like to see a .adult
domain. "We’re suggesting the creation of a new top-level domain
called ’.adult’ where all sexually explicit material on the Net would
reside," Warshavsky said in an interview at the time [WARSHAVSKY].
More recently, other entrepreneurs in the industry have said that
they do not necessarily object to the creation of an adult domain as
long as they may continue to use .com.
Conservative groups in the U.S. say they are not eager for such a
domain, and prefer criminal laws directed at publishers and
distributors of sexually-explicit material. The National Law Center
for Children and Families in Fairfax, Virginia, said in February 2001
that it did not favor any such proposal. For different reasons, the
American Civil Liberties Union and other civil liberties groups also
oppose it.
Sen. Joseph Lieberman, the U.S. Democratic Party’s vice presidential
nominee, endorsed the idea at a June 2000 meeting of the federal
Commission on Child Online Protection. Lieberman said in a prepared
statement that "we would ask the arbiters of the Internet to simply
abide by the same standard as the proprietor of an X-rated movie
theater or the owner of a convenience store who sells sexually-
explicit magazines" [LIEBERMAN].
In the 1998 law creating this commission, the U.S. Congress required
the members to investigate "the establishment of a domain name for
posting of any material that is harmful to minors", The commission
devoted a section of its October 2000 report to that topic. It
concluded that both a .xxx and a .kids domain are technically
possible, but would require action by ICANN. The report said that an
adult domain might be only "moderately effective" and raises privacy
and free speech concerns [COPAREPORT].
The commission also explored the creation of a so-called red zone or
green zone for content by means of allocation of a new set of IP
addresses under IPv6. Any material not in one of those two zones
would be viewed as in a gray zone and not necessarily appropriate or
inappropriate for minors. Comments from commissioners were largely
negative: "Effectiveness would require substantial effort to attach
content to specific IP numbers. This approach could potentially
reduce flexibility and impede optimal network performance. It would
not be effective at blocking access to chat, newsgroups, or instant
messaging".
In October 2000, ICANN rejected a .xxx domain during its initial
round of approving additional top-level domains. The reasons are not
entirely clear, but former ICANN Chairwoman Esther Dyson said that
the adult industry did not entirely agree that such a domain would be
appropriate. One .xxx hopeful, ICM Registry of Ontario, Canada, in
December 2000 asked ICANN to reconsider its decision [ICM-REGISTRY].
In 2002, the U.S. Congress mandated the creation of a kids.us domain
for "child safe" material. This was after being convinced that for
reasons, some of which are described in the following section, trying
to legislate standards for the whole world with a .kids domain was
inappropriate.
3. Legal and Philosophical Problems
When it comes to sexually-explicit material, every person, court, and
government has a different view of what’s acceptable and what is not.
Attitudes change over time, and what is viewed as appropriate in one
town or year may spark protests in the next. When faced with the
slippery nature of what depictions of sexual activity should be
illegal or not, one U.S. Supreme Court justice blithely defined
obscenity as: "I know it when I see it".
In the U.S.A., obscenity is defined as explicit sexual material that,
among other things, violates "contemporary community standards" -- in
other words, even at the national level, there is no agreed-upon rule
governing what is illegal and what is not. Making matters more
knotty is that there are over 200 United Nations country codes, and
in most of them, political subdivisions can impose their own
restrictions. Even for legal nude modeling, age restrictions differ.
They’re commonly 18 years of age, but only 17 years of age in one
Scandinavian country. A photographer there conducting what’s viewed
as a legal and proper photo shoot would be branded a felon and child
pornographer in the U.S.A. In yet other countries and groups, the
entire concept of nude photography or even any photography of a
person in any form may be religiously unacceptable.
Saudi Arabia, Iran, Northern Nigeria, and China are not likely to
have the same liberal views as, say, the Netherlands or Denmark.
Saudi Arabia and China, like some other nations, extensively filter
their Internet connection and have created government agencies to
protect their society from web sites that officials view as immoral.
Their views on what should be included in a .sex domain would hardly
be identical to those in liberal western nations.
Those wildly different opinions on sexual material make it
inconceivable that a global consensus can ever be reached on what is
appropriate or inappropriate for a .sex or .adult top-level domain.
Moreover, the existence of such a domain would create an irresistible
temptation on the part of conservative legislators to require
controversial publishers to move to that domain and punish those who
do not.
Some conservative politicians already have complained that ICANN did
not approve .xxx in its October 2000 meeting. During a February 2001
hearing in the U.S. House of Representatives, legislators warned that
they "want to explore ICANN’s rationale for not approving two
particular top level domain names -- .kids and .xxx -- as a means to
protect kids from the awful smut which is so widespread on the
Internet".
It seems plausible that only a few adult publishers, and not those
who have invested resources in building a brand around a .com site,
would voluntarily abandon their current domain name. Instead, they’d
likely add a .xxx variant and keep their original address. The
existence of .xxx could propel legislators in the U.S. and other
countries to require them to publish exclusively from an adult
domain, a move that would invite ongoing political interference with
Internet governance, and raise concerns about forced speech and
self-labeling.
In fact, the ultimate arbiter of generic top-level domain names -- at
least currently -- is not ICANN, but the U.S. government. The U.S.
Congress’ General Accounting Office in July 2000 reported that the
Commerce Department continues to be responsible for domain names
allowed by the authoritative root [GAO]. The GAO’s auditors
concluded it was unclear whether the Commerce Department has the
"requisite authority" under current law to transfer that
responsibility to ICANN.
The American Civil Liberties Union -- and other members of the
international Global Internet Liberty Campaign -- caution that
publishers speaking frankly about birth control, AIDS prevention, gay
and lesbian sex, the social problem of prison rape, etc., could be
coerced into moving to an adult domain. Once there, they would be
stigmatized and easily blocked by schools, libraries, companies, and
other groups using filtering software. Publishers of such
information, who do not view themselves as pornographers and retain
their existing addresses, could be targeted for prosecution.
The existence of an adult top-level domain would likely open the door
for related efforts, either policy or legislative. There are many
different axes through which offensive material can be defined: Sex,
violence, hate, heresy, subversion, blasphemy, illegal drugs,
profanity, political correctness, glorification of crime, incitement
to break the law, and so on. Such suggestions invite the ongoing
lobbying of ICANN, the U.S. government, and other policy-making
bodies by special-interest groups that are not concerned with the
technical feasibility or practicality of their advice.
An adult top-level domain could have negative legal repercussions by
endangering free expression. U.S. Supreme Court Justice Sandra Day
O’Connor has suggested that the presence of "adult zones" on the
Internet would make a future Communications Decency Act (CDA) more
likely to be viewed as constitutional. In her partial dissent to the
Supreme Court’s rejection of the CDA in 1997 [CDA], O’Connor said
that "the prospects for the eventual zoning of the Internet appear
promising". (The Supreme Court ruled that the CDA violated free
speech rights by making it a crime to distribute "indecent" or
"patently offensive" material online.)
Privacy could be harmed by such a proposal. It would become easier
for repressive governments and other institutions to track visits to
sites in a domain labeled as adult and record personally-identifiable
information about the visitor. Repressive governments would
instantly have more power to monitor naive users and prosecute them
for their activities. It’s also implausible that a top-level domain
would be effective in controlling access to chat, email, newsgroups,
instant messaging, and new services as yet to be invented.
4. Technical Difficulties
Even ignoring the philosophical and legal difficulties outlined
above, there are substantial technical difficulties in attempting to
impose content classification by domain names or IP addresses.
Mandatory content labeling is usually advanced with the idea of using
a top level domain name, discussed in section 4.1., but we also
discuss the possibility of using IP address bits or ranges in section
4.2.
In section 4.1.4., difficulties with a few particular higher level
protocols are discussed. In some cases, these protocols use
different name spaces. It should be kept in mind that additional
future protocols may be devised with as yet undreamed of naming
characteristics.
We also discuss PICS labels [PICS] as an alternative technology in
section 4.3.
Only a limited technical background is assumed, so some basic
information is included below. In some cases, descriptions are
simplified and details omitted.
This technical discussion minimizes the definitional problems.
However, it is still necessary for evaluating some technical
considerations to have some estimate of the amount of categorization
that would be necessary for a realistic global censorship system.
There is no hope of agreement on this point. For our purposes, we
will arbitrarily assume that the world’s population consists of
approximately 90,000 overlapping communities, each of which would
have a different categorization of interest. Further, we arbitrarily
assume that some unspecified but clever encoding scheme enables a
proper global categorization of all information by a 300 bit label.
Some would say a 300 bit label is too large, others that it is too
small. Regardless, we will use it for some technical evaluations.
4.1. Content Filtering Using Names
The most prominent user visible part of Internet naming and
addressing is the domain name system [RFC 1034, 1035]. Domain Names
are dotted sequences of labels, such as aol.com, world.std.com,
www.rosslynchapel.org.uk, or ftp.gnu.lcs.mit.edu [RFC 1035, 1591,
2606]. Domain Names form an important part of most World Wide Web
addresses or URLs [RFC 2396], commonly appearing after "//".
Security for the domain name system is being standardized [RFC 2535],
but has not been deployed to any significant extent.
Domain names designate nodes in a globally distributed hierarchically
delegated database. A wide variety of information can be stored at
these nodes, including IP addresses of machines on the network (see
section 4.2. below), mail delivery information, and other types of
information. Thus, the data stored at foo.example.com could be the
numeric information for sending data to a particular machine, which
would be used if you tried to browse <http://foo.example.com>, the
name of a computer (say mailhost.example.com) to handle mail
addressed to anyone "@foo.example.com", and/or other information.
There are also other naming systems in use, such as news group names
and Internet Relay Chat (IRC) channel names.
The usual labeling idea presented is to reserve a top level name,
such as .sex or .xxx for "adult" material and/or .kids for "safe"
material or the like. The technical and linguistic problems with
this are described in the subsections below.
4.1.1. Linguistic Problems
When using name labeling, the first problem is from whose language do
you take the names to impose? Words and acronyms can have very
different meanings in different languages and the probability of
confusion is multiplied when phonetic collisions are considered.
As an example of possible problems, note that for several years the
government of Turkmenistan suspended new registrations in ".tm",
which had previously been a source of revenue, because some of the
registered second level domain names may have been problematic. In
particular, their web home page at <http://www.nic.tm> said:
Statement from the .TM NIC
"The response to the .TM registry has been overwhelming.
Thousands of names have been registered from all over the
world. Some of the names registered, however, may be legally
obscene in Turkmenistan, and as a result the .TM NIC registry
is reviewing its naming policy for future registrations. The
.TM NIC has suspended registrations until a new policy can be
implemented. We hope to be live again shortly."
There are approximately 6,000 languages in use in the world today,
although this is expected to decline to around 3,000 by the year
2100.
4.1.2. Explosion of Top Level Domain Names (TLDs)
An important aspect of the design of the Domain Name System (DNS) is
the hierarchical delegation of data maintenance. The DNS really only
works, and has been able to scale over the five orders of magnitude
it has grown since its initial deployment, due to this delegation.
The first problem is that one would expect most computers or web
sites to have a mix of material, only some of which should be
specially classified. Using special top level domain names (TLDs)
multiplies the number of DNS zones the site has to worry about. For
example, assume the site has somehow already sorted its material into
"kids", "normal", and "adult" piles. Without special TLD labels, it
can store them under kids.example.net, adult.example.net, and
other.example.net, for instance. This would require only the
maintenance of the single example.net zone of database entries. With
special TLD labeling, at least example.net (for normal stuff),
example.net.sex, and example.net.kids would need to be maintained,
which are in three separate zones, in different parts of the DNS
tree, under three separate delegations.
As the number of categories expands, the number of category
combinations explodes, and this quickly becomes completely
unmanageable. If 300 bits worth of labeling is required, the system
could, in theory, need 2**300 name categories, an impossibility. No
individual site would need to use all categories and the category
domain names would not all have to be top level names. But it would
still be an unmanageable nightmare.
4.1.3. You Can’t Control What Names Point At You!
Providers of data on the Internet cannot stop anyone from creating
names pointing to their computer’s IP address with misleading domain
names.
The DNS system works as a database. It associates certain data,
called resource records, or RRs, with domain names. In particular,
it can associate IP address resource records with domain names. For
example, when you browse a URL, most commonly a domain name within
that URL is looked up in the DNS. The resulting address is then used
to address the packets sent from your web browser or other software
to the server or peer.
Remember what we said in Section 4.1.1. about hierarchical
delegation? Control is delegated and anyone controlling a DNS zone
of data, say example.com, can insert data at that name or any deeper
name (except to the extent that they delegate some of the deeper
namespace to yet others). So the controller of example.com can
insert data so that purity.example.com has, associated with it, the
same computer address, which is associated with
www.obscene.example.sex. This directs any reference to
purity.example.com to use the associated IP address which is the same
as the www.obscene.example.sex web site. The manager of that
hypothetical web site, who controls the obscene.example.xxx zone, has
no control over the example.com DNS zone. They are technically
incapable of causing it to conform to any ".sex" labeling law. In
the alternative, someone could create a name conforming to an adult
labeling requirement, such as foo.stuff.sex, that actually pointed to
someone else’s entirely unobjectionable site, perhaps for the purpose
of polluting the labeling. See diagram below. Each "zone" could be
hosted on a different set of physical computers.
+-----------------------------------------+
| . (root) zone |
| .com .org .net .us .uk .sex ... |
+---+---------------------------+---------+
| |
V V
+--------------------+ +--------------------+
| .com zone | | .sex zone |
| example.com ... | | example.sex ... |
+---------------+----+ +---------------+----+
| |
V V
+---------------------+ +----------------------+
| example.com zone | | example.sex zone |
| | | |
| purity.example.com -+--+ +---+- obscene.example.sex |
| virtue.example.com | | | | porn.example.sex |
| | | | | | | |