Internet censorship, Asia leading the way...

The Geopolitics of Asian Cyberspace
December 2006, by Ronald Deibert in FEER

When the ONI was formed in 2002, only a handful of countries were known to engage in Internet content filtering, most prominently China, Iran and Saudi Arabia. Now more than four years later, the ONI is presently testing in more than 40 countries worldwide. China is still the world’s most notorious and sophisticated censoring regime. Its filtering system comprises multiple levels of legal regulation and technical control, the latter implemented primarily at the backbone level using specially configured Cisco routers. The system involves numerous state agencies and thousands of public and private personnel, and a dense web of ever-thickening legal restrictions.

However, China is not alone. Among countries that the ONI has researched in Asia, we have technically confirmed Internet content filtering in Burma, Vietnam, the Maldives, Thailand, South Korea, Singapore, Pakistan and India. Although we have not yet conducted tests in North Korea, it is well known that what little Internet exists in the country is heavily filtered. Likewise, Australia filters Web content through official takedown notices issued to ISPs by the government. In Central Asia, we have also identified extensive Internet censorship practices in Uzbekistan, and intermittent or targeted filtering in Kazakhstan, Kyrgyzstan and Tajikistan. (...)

While some authorities yield clearly labeled blockpages to users who request banned content, others are not so transparent. In China, for example, ONI researchers found through forensic analysis that China’s backbone routers are configured such that requests for banned content result in a network timeout error. The routers then send packets to the user’s machine effectively blocking that user’s unique IP address for an indefinite period of time such that any further requests for any web content on the same server results in a network timeout error. Among some ISPs in Uzbekistan, requests for search engines or political opposition Web sites are redirected to search engine Web sites.

Other interesting webpages (from the OpenNet Initiative):

Previous efforts to document the extent of government filtering have been made by researchers at the Soros Foundation's Internet Censorship Project. In that work, the ICP sent correspondents around the world to collect anecdotal data about filtering efforts worldwide by manually searching for some well-known Web pages; we build on their work by invoking automated methods to test and document thousands of pages blocked by each country or other blocking system studied. We wish to similarly augment the efforts described in such ventures as Shanthi Kalathil and Taylor Boas's "The Internet and State Control in Authoritarian Regimes" and Radio Free Europe's "20 Enemies of the Internet." Finally, our work follows a series of projects intended to document sites blocked -- and in many instances arguably wrongly blocked -- by major commercial Internet filtering applications; such projects include Bennett Haselton's Peacefire and Seth Finkelstein's Anticensorware Investigations as well as one author's Sites Blocked by Internet Filtering Programs.