who can access the Internet, as Myanmar has, in order to keep URL filtering manageable—or
to be able to shut off access to the network entirely, as the military junta appears to have done
in September 2007.
Technical Internet filtering is not perfect in any jurisdiction. Even the most sophisticated
technical filtering regimes can have difficulty covering those cases where users are intent on
getting or publishing certain information, and willing to invest effort and risk to do so. Every
system suffers from at least two shortcomings: a technical filtering system either underblocks
or overblocks content, and technically savvy users can circumvent the controls with a modicum of effort. Citizens with technical knowledge can generally circumvent any filters that a
state has put in place. Some states acknowledge as much: the overseer of Saudi Arabia’s
filtering program admits that technically savvy users simply cannot be stopped from accessing blocked content.
11 While no state will ultimately win the game of cat-and-mouse with those
citizens who are resourceful and dedicated enough to employ circumvention measures, many
users will never do so.
For some states, like Singapore, the state’s bark is worse than the bite of the filtering system. The widely publicized Singaporean filtering system blocks only a small handful of pornographic sites. The Singapore system is more about sending a message, one that underscores
the substantial local self-censorship that takes place there, than it is about blocking citizens
from accessing or publishing anything specific. For other states, like those with the most thorough and sophisticated filtering regimes—for instance, China, Iran, and Uzbekistan—the undertaking is far more substantial and has far-reaching consequences.
Locus of Filtering
Most state-mandated filtering is effected by private ISPs that offer Internet access to citizens under licenses to operate in that jurisdiction. These licenses tend to include requirements, explicit or implicit in nature, that the ISPs implement filtering at the behest of the
state. Some states partially centralize the filtering operation at private Internet exchange points
(IXPs)—topological crossroads for network traffic—or through explicit state-run clearing
points established to serve as gatekeepers for Internet traffic. Some states implement filtering at public Internet access points, such as the computers found within cybercafe ´s or in public libraries and schools, as in the United States. Such filtering can take the form of software
used in many American libraries and schools for filtering purposes, or normative filtering—
government-encouraged social pressure by shop proprietors, librarians, and others as citizens surf the Internet in common public places.
The exercise of traditional state powers can have a powerful impact on Internet usage without rendering all content in a particular category inaccessible. China, Vietnam, and Iran,
among others, have each jailed ‘‘cyber-dissidents.’’
12 Against this backdrop, the blocking of
Web pages may be intended to deliver a message to users that the government monitors
Internet usage. This message is reinforced by methods allowing information to be gathered
34
Jonathan Zittrain and John Palfrey
to be able to shut off access to the network entirely, as the military junta appears to have done
in September 2007.
Technical Internet filtering is not perfect in any jurisdiction. Even the most sophisticated
technical filtering regimes can have difficulty covering those cases where users are intent on
getting or publishing certain information, and willing to invest effort and risk to do so. Every
system suffers from at least two shortcomings: a technical filtering system either underblocks
or overblocks content, and technically savvy users can circumvent the controls with a modicum of effort. Citizens with technical knowledge can generally circumvent any filters that a
state has put in place. Some states acknowledge as much: the overseer of Saudi Arabia’s
filtering program admits that technically savvy users simply cannot be stopped from accessing blocked content.
11 While no state will ultimately win the game of cat-and-mouse with those
citizens who are resourceful and dedicated enough to employ circumvention measures, many
users will never do so.
For some states, like Singapore, the state’s bark is worse than the bite of the filtering system. The widely publicized Singaporean filtering system blocks only a small handful of pornographic sites. The Singapore system is more about sending a message, one that underscores
the substantial local self-censorship that takes place there, than it is about blocking citizens
from accessing or publishing anything specific. For other states, like those with the most thorough and sophisticated filtering regimes—for instance, China, Iran, and Uzbekistan—the undertaking is far more substantial and has far-reaching consequences.
Locus of Filtering
Most state-mandated filtering is effected by private ISPs that offer Internet access to citizens under licenses to operate in that jurisdiction. These licenses tend to include requirements, explicit or implicit in nature, that the ISPs implement filtering at the behest of the
state. Some states partially centralize the filtering operation at private Internet exchange points
(IXPs)—topological crossroads for network traffic—or through explicit state-run clearing
points established to serve as gatekeepers for Internet traffic. Some states implement filtering at public Internet access points, such as the computers found within cybercafe ´s or in public libraries and schools, as in the United States. Such filtering can take the form of software
used in many American libraries and schools for filtering purposes, or normative filtering—
government-encouraged social pressure by shop proprietors, librarians, and others as citizens surf the Internet in common public places.
The exercise of traditional state powers can have a powerful impact on Internet usage without rendering all content in a particular category inaccessible. China, Vietnam, and Iran,
among others, have each jailed ‘‘cyber-dissidents.’’
12 Against this backdrop, the blocking of
Web pages may be intended to deliver a message to users that the government monitors
Internet usage. This message is reinforced by methods allowing information to be gathered
34
Jonathan Zittrain and John Palfrey