China Blocks Uncensored Version of Wikipedia Ahead of Tiananmen Square Anniversary

Sina Weibo, the country’s popular Twitter-like service, has also been observed suddenly experimenting with more sophisticated censorship techniques.

In the days leading up to the 24th anniversary of the Tiananmen Square massacre on Tuesday, the Chinese government has been closing some cracks in its system of Internet censorship, known as the Great Firewall, according to reports.

On Monday, access to an uncensored version of Wikipedia was cut off in the country, according to Greatfire, an organization that monitors online censorship in China.

Beginning Oct. 2011, Wikipedia began supporting encrypted connections to all local language versions of its behemoth encyclopedia, which prevents Chinese censors from selectively blocking articles from the site. As of Monday, however, only the old, unencrypted version of the Chinese-language Wikipedia -- which is missing hundreds of entries on politically sensitive topics -- is accessible in the country.

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Most analysts have linked the crackdown to the always politically sensitive anniversary of the June 4, 1989, massacre of pro-democracy student protesters in Tiananmen Square. Hundreds of students were killed in the military suppression of the protests, but the Chinese government has yet to provide an official death toll, as it still views the protests as criminal and “counter revolutionary.”

Greatfire also reported that it had noticed a shift in the censorship tactics used on Sina Weibo, China’s wildly popular Twitter-like microblog service. In the past, the site blocked searches for hundreds of keywords deemed politically fraught. But as of Friday, for example, searches for “June 4 incident” -- as the event is known in China -- began yielding results.

In the past, searching for this hot-button issue would yield an error message or a statement saying that the given search term had been blocked for legal reasons. For less overtly sensitive topics, searches would result in a filtered list of harmless posts that were several days old – suggesting both that the search term was censored and that it took several days for Sina to winnow politically inflammatory content from its millions of posts.

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As of Friday, search results for sensitive topics began leading to filtered, harmless results that were just several hours old -- with no notice that the tweets had in any way been censored. From the user’s end, this new speed and sophistication in filtering makes it harder to tell which search terms are being meddled with -- instead, it will often appear as if a censored search term is being openly discussed, but nothing controversial is being said about it.

“This is an example of censorship at its worst,” wrote Greatfire. “Users suspect their search term might get blocked before they search but instead of a censorship notice they are led to believe that what they are searching for is not sensitive, plus not many people are saying anything interesting about the keyword anyway.”

On Friday, the U.S. State Department issued a statement of remembrance for those killed in Tiananmen Square, calling on the Chinese government to "end harassment of those who participated in the protests and fully account for those killed, detained or missing."

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Chinese foreign ministry spokesman Hong Lei replied with a statement demanding that the United States “discard political prejudice, correctly treat China's development, immediately rectify its wrongdoings and stop interfering in China's internal affairs so as not to sabotage China-U.S. relations."