Regulating Online Speech
Week 3 - January 30, February 1
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Administrivia
Questions about retaking the quiz?
• Questions about proper citations and avoiding
plagiarism?
Homework #2 now posted
http://cups.cs.cmu.edu/courses/compsocsp07/homework/hw2.html
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Homework 1 discussion
How would your life be different without
computers?
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Research and Communication Skills
CMU Libraries
(http://www.library.cmu.edu)
 Engineering and Science (a.k.a. E&S)
• Location: 4th floor, Wean Hall
• Subjects: Computer Science, Engineering, Mathematics,
Physics, Science, Technology
 Hunt (CMU’s main library)
• Location: its own building (possibly 2nd ugliest on campus
behind Wean), between Tepper and Baker
• Subjects: Arts, Business, Humanities, Social Sciences
 Software Engineering Institute (a.k.a. SEI)
• Location: 4500 5th Avenue
• Subjects: “Security, Software, Technology”
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Research and Communication Skills
Coolest Thing in CMU Libraries
Posner Memorial Collection at Posner
Center
• Rare books
• Early prints of famous works
• Original copy of the Bill of Rights
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Research and Communication Skills
START HERE: Cameo
Cameo is CMU’s online library catalog
Catalogs everything CMU has – books,
journals, periodicals, multimedia, etc.
Search Cameo online at
http://cameo.library.cmu.edu
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Research and Communication Skills
If it’s not in Cameo, but you need it
today: Local Libraries
Carnegie Library of Pittsburgh
http://www.carnegielibrary.org/index.html
University of Pittsburgh Libraries
http://pittcat.pitt.edu/
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Research and Communication Skills
If it’s not in Cameo, and you can wait:
ILLiad and E-ZBorrow
 ILLiad and E-ZBorrow are catalogs of resources available
for Interlibrary Loan from other libraries nationwide
(ILLiad) and in Pennsylvania (E-ZBorrow)
 Order items online (almost always free)
 Wait for delivery – average 10 business days
 Find links to ILLiad and E-ZBorrow online catalogs at
http://www.library.cmu.edu/Services/ILL/
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Research and Communication Skills
Special needs: Other Useful
Databases
 Links to these and many more databases available at
http://www.library.cmu.edu/Search/AZ.html
 Lexis-Nexis
• Massive catalog of legal sources – law journals, case law,
news stories, etc.
 IEEE and ACM journal databases
• IEEE Xplore and ACM Digital Library
 INSPEC database
• Huge database of scientific and technical papers
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Research and Communication Skills
And of course…
Reference librarians are available at all
CMU libraries, and love to help people find
what they need – just ask!
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Bill of Rights
First Amendment
• Congress shall make no law respecting an
establishment of religion, or prohibiting the free
exercise thereof; or abridging the freedom of
speech, or of the press; or the right of the
people peaceably to assemble, and to petition
the government for a redress of grievances.
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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The Internet can’t be censored
“The Net treats censorship as damage and
routes around it.”
- John Gillmore
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Cartoon dogs are anonymous on the Internet
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Real dogs are anonymous on the Internet too!
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Actually, none of this is true
It is easy to adopt a pseudonym or a
persona on the Internet, but it is difficult to
be truly anonymous
• Identities can usually be revealed with
cooperation of ISP, local sys-admins, web logs,
phone records, etc.
The Internet can put up a good fight against
censorship, but in the end there is still a lot
of Internet censorship
• Repressive governments and intellectual
property lawyers have been pretty successful
at getting Internet content removed
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Communications Decency Act
 Title V of the Telecommunications Act of 1996
 Prohibited Internet distribution of indecent or patently
offensive material to minors
 Created restrictions for the Internet similar to broadcast
media
 Introduced by Sen. James Exon (D-Nebraska)
• Cited Marty Rimm study
• http://www.swiss.ai.mit.edu/6095/articles/cda/saga.html
 Immediately challenged in court
 Supreme Court struck down CDA in 1997 (Reno v.
American Civil Liberties Union)
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Opposition to the CDA
 Over-broad, vague, unenforceable
 CDA includes “indecency standard”
•
•
Obscenity and child pornography are already illegal to distribute (child
pornography is also illegal to possess)
Obscenity - Miller test:
 Whether the average person, applying contemporary community standards, would find
that the work, taken as a whole, appeals to the prurient interest,
 Whether the work depicts/describes, in a patently offensive way, sexual conduct
specifically defined by applicable state law,
 Whether the work, taken as a whole, lacks serious literary, artistic, political, or scientific
value.
•
But indecency is defined in CDA as “any comment, request, suggestion, proposal,
image, or other communications, that, in context, depicts or describes, in terms
patently offensive as measured by contemporary community standards, sexual or
excretory activities or organs.”
 What community do we look at when regulating the Internet?
 Internet should not be regulated like broadcast
 Law would chill free speech
 Internet filters are a better solution
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Support for the CDA
Senator James Exon (D-Nebraska),
sponsor of Bill: Need to protect children
from online pornography
Laws that restrict selling porn to children in
other media should apply to the Internet
Filters are not sufficient
• Parents may not be able to figure out how to
use them
• Children may access computers away from
home
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Platform for Internet Content Selection (PICS)
Developed by the World Wide Web
Consortium
Specification for associating metadata with
Internet content
• Supports self-labels and third-party labels
• Supports the development of many rating
systems
Implemented in MS Internet Explorer and
other products
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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How technology tools work
Internet
content
Web
Usenet
Email
Chat
Gopher
FTP
Person or
tool classifies
content
For what age
group is it
appropriate?
Is it educational?
Tool takes
an action
Suggest
Search
Inform
Monitor
Warn
Block
Is it fun?
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Who does the classification?
Third-party experts
Automated tools
Local administrators
Content providers
Survey or vote
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Classification scheme
Good for kids
Characteristics of
content
Bad for kids
Age suitability
Who created content
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Rating systems and vocabularies
Math
Science
English
Spelling
History
French
Spanish
Gym
Art
Music
Drama
A
B
B+
DC
AF
A+
BC
B
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Descriptive versus subjective
Many
variables
Few
variables
complex
simple
Subjective
Descriptive
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Can’t derive descriptive from subjective
Characters not well developed
Gratuitous sex and violence
?
Bad acting?
Boring plot?
Bad script?
Dull characters?
Unbelievable premise?
Unoriginal?
Too much violence?
Not enough violence?
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Scope
Web sites
FTP, gopher, etc.
Chat
Instant messaging
Newsgroups
Email
Telnet
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Actions
Suggest
Search
Inform
Monitor
Warn
Block
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Mechanisms and interface
Location
Updates
Customizability
Other features
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Where are the tools located?
 Personal computer
 Server
• LAN or
local proxy
• Remote proxy
 Internet service
provider
 Search engine
 Web site
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Updates
How are tools updated?
• Manual updates required
• Automatic updates
• No updates required
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Customizability
 Action
 Words and phrases
 Allow and block list
elements
 Time of day
 Policies for each user
 Categories of content
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Other features
Time limits
Separate settings for each child
Protect parents’ files
Block individual words and pictures vs. full
page or whole site
Explanation of why blocked vs. silent
blocking
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Discussion
Diversity of tools in the marketplace is
important
Need for increased transparency from
vendors about the criteria used to classify
content
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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CDA Sequels
 Child Online Protection Act (COPA) - passed in 1998
• Banned commercial distribution of material harmful to minors
• ACLU challenged this law - Supreme Court has twice upheld
lower court injunctions against enforcement, back to lower court in
October 2006
• http://www.aclu.org/freespeech/internet/onlinefreespeech.html
 Children’s Internet Protection Act (CIPA) passed in 1999
• Requires schools and libraries that receive federal funds for
Internet access to filter out child pornography, obscene materials,
and materials harmful to minors
• Upheld by Supreme Court in 2003
 Many state laws
• Most have been declared unconstitutional
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Anonymous censorship-resistant publishing
 The printing press and the WWW can be
powerful revolutionary tools
• Political dissent
• Whistle blowing
• Radical ideas
 but those who seek to suppress revolutions have
powerful tools of their own
•
•
•
•
Stop publication
Destroy published materials
Prevent distribution
Intimidate or physically or financially harm author or
publisher
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Anonymity increases censorship-resistance
 Reduces ability to force “voluntary” selfcensorship
 Allows some authors to have their work taken
more seriously
• Reduces bias due to gender, race, ethnic background,
social position, etc.
 Many historical examples of important
anonymous publications
• In the Colonies during Revolutionary War when British
law prohibited writings suggesting overthrow of the
government
• Federalist papers
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Publius design goals
 Censorship resistant
 Tamper evident
 Source anonymous
 Updateable
 Deniable
 Fault tolerant
 Persistent
 Extensible
 Freely Available
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Publius Overview
Publishers
Servers
Retrievers
 Publius Content – Static content (HTML, images, PDF, etc)
 Publishers – Post Publius content
 Servers – Host Publius content
 Retrievers – Browse Publius content
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Publishing a Publius document
Publishers
Servers
 Generate secret key and use it to encrypt document
 Use “secret splitting” to split key into n shares
• This technique has special property that only k out of n shares are
needed to put the key back together
 Publish encrypted document and 1 share on each of n servers
 Generate special Publius URL that encodes the location of each
share and encrypted document – example:
http://!publius!/1e6adsg673h0==hgj7889340==345lsafdfg
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Retrieving a Publius document
Publishers
Servers
Retrievers
 Break apart URL to discover document locations
 Retrieve encrypted document and share from k locations
 Reassemble key from shares
 Decrypt retrieved document
 Check for tampering
 View in web browser
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Publius proxies
Publishers
Servers
P
R
O
X
Y
Retrievers
P
R
O
X
Y
 Publius proxies running on a user’s local machine
or on the network handle all the publish and
retrieve operations
 Proxies also allow publishers to delete and
update content
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Threats and limitations
 Attacks on server resources
• 100K Content Limit (easy to subvert)
• Server limits # of files it will store
• Possibility: use a payment scheme
 Threats to publisher anonymity
 “Rubber-Hose Cryptanalysis”
• Added “don’t update” and don’t delete bit
 Logging, network segment eavesdropping
 Collaboration of servers to censor content
• A feature?
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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Discussion
Technology that can protect “good” speech
also protects “bad” speech
What if your dog does publish your secrets
to the Internet and you can't do anything
about it?
Is building a censorship-resistant publishing
system irresponsible?
If a tree falls in a forest and nobody hears
it….
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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For further reading
Publius web site
http://cs.nyu.edu/waldman/publius.html
Publius chapter in Peer-to-Peer:
Harnessing the Power of
Disruptive Technologies edited
by Andy Oram
The Architecture of Robust Publishing
Systems. ACM Transactions on Internet
Technology 1(2):199-230
http://doi.acm.org/10.1145/502152.502154
Computers and Society • Carnegie Mellon University • Spring 2007 • Cranor/Tongia • http://cups.cs.cmu.edu/courses/compsoc-sp07/
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