(mirrorbooks.com) using this method. China Unicom also used IP blocking to filter
nearly 400 IP addresses. These correlated closely with sites blocked on CT through a
method obscured to analysis, in which users were presented with an error page informing the user that a network error occurred while accessing the Web site. While the error
page can appear in the case of legitimate network errors, the repeated appearance of
the error page indicates blocking is taking place. China Telecom also used a squid
proxy to block a handful of Web sites, including several Flickr photo servers. While
the two backbone providers showed less overlap in filtering methods when compared
with 2006–2007, there continued to be almost complete correlation in blocking between CU and CT.
At time of testing, most international social media platforms were accessible, including Flickr, Blogspot, Wordpress, Facebook, and Twitter. In contrast to 2006–2007,
when all individual Blogspot blogs tested were accessible on China Netcom and
blocked or inaccessible on China Telecom, in 2008 CU and CT blocked nearly all of
the same individual Blogspot blogs tested. Technorati continued to be blocked.
In late 2008, China had resumed blocking many Web sites that were blocked in
2006–2007 and made accessible during at least part of the Olympics period. These
included the independent overseas news sites (The Liberty Times) and Radio Free Asia’s
main Web site and its Mandarin-, Uyghur-, and Tibetan-language sites. However, in
contrast to 2006–2007, some of these Web sites were unreliably or intermittently
accessible during December 2008 testing, possibly as a result of the TCP reset filtering
method used. Sites blocked using the TCP reset included YouTube, Chinese-language
Wikipedia, and BBC News.
A few sites that were accessible in 2006–2007 had been blocked by 2008 testing,
most notably Wikipedia (en.wikipedia.org). The site Wikileaks (www.wikileaks.org)
was also blocked by both ISPs in 2008 testing.
The greatest variations in filtering patterns between 2006–2007 and 2008 occurred
with Chinese-language news media Web sites, likely in continuity from the Olympics.
As in 2006–2007, few international news organizations were filtered, and some formerly blocked (e.g., Voice of America news) were accessible. Notably, some prominent
Chinese-language media blocked in 2006–2007 were accessible in 2008, including the
World Journal, www.singtao.com, and the Apple Daily. However, a significant number
of independent media representing different points on the political spectrum continued to be filtered.
In 2006–2007 and 2008, China filtered a significant portion of content specific to its
own human rights record and practices. As such, only a few global human rights sites
with a global scope continued to be filtered, including Human Rights and Freedom
House. Article 19 and Human Rights First were no longer blocked in 2008, and filtering
on Amnesty International was renewed after a hiatus during the Olympics period. A
typical example of this targeting of China-related content is the differential treatment
470
China
nearly 400 IP addresses. These correlated closely with sites blocked on CT through a
method obscured to analysis, in which users were presented with an error page informing the user that a network error occurred while accessing the Web site. While the error
page can appear in the case of legitimate network errors, the repeated appearance of
the error page indicates blocking is taking place. China Telecom also used a squid
proxy to block a handful of Web sites, including several Flickr photo servers. While
the two backbone providers showed less overlap in filtering methods when compared
with 2006–2007, there continued to be almost complete correlation in blocking between CU and CT.
At time of testing, most international social media platforms were accessible, including Flickr, Blogspot, Wordpress, Facebook, and Twitter. In contrast to 2006–2007,
when all individual Blogspot blogs tested were accessible on China Netcom and
blocked or inaccessible on China Telecom, in 2008 CU and CT blocked nearly all of
the same individual Blogspot blogs tested. Technorati continued to be blocked.
In late 2008, China had resumed blocking many Web sites that were blocked in
2006–2007 and made accessible during at least part of the Olympics period. These
included the independent overseas news sites (The Liberty Times) and Radio Free Asia’s
main Web site and its Mandarin-, Uyghur-, and Tibetan-language sites. However, in
contrast to 2006–2007, some of these Web sites were unreliably or intermittently
accessible during December 2008 testing, possibly as a result of the TCP reset filtering
method used. Sites blocked using the TCP reset included YouTube, Chinese-language
Wikipedia, and BBC News.
A few sites that were accessible in 2006–2007 had been blocked by 2008 testing,
most notably Wikipedia (en.wikipedia.org). The site Wikileaks (www.wikileaks.org)
was also blocked by both ISPs in 2008 testing.
The greatest variations in filtering patterns between 2006–2007 and 2008 occurred
with Chinese-language news media Web sites, likely in continuity from the Olympics.
As in 2006–2007, few international news organizations were filtered, and some formerly blocked (e.g., Voice of America news) were accessible. Notably, some prominent
Chinese-language media blocked in 2006–2007 were accessible in 2008, including the
World Journal, www.singtao.com, and the Apple Daily. However, a significant number
of independent media representing different points on the political spectrum continued to be filtered.
In 2006–2007 and 2008, China filtered a significant portion of content specific to its
own human rights record and practices. As such, only a few global human rights sites
with a global scope continued to be filtered, including Human Rights and Freedom
House. Article 19 and Human Rights First were no longer blocked in 2008, and filtering
on Amnesty International was renewed after a hiatus during the Olympics period. A
typical example of this targeting of China-related content is the differential treatment
470
China