The Stunning Speed of Internet Censorship in China

The result of searching for Amnesty International from Yahoo India. (Brad T./China Gaze)
The result of searching for Amnesty International from Yahoo India. (Brad T./China Gaze)

Sina Weibo’s team of “editors” at the heart of world’s largest effort to control social media. It takes minutes, according to a new study on the mechanics of censorship on China’s most popular microblogging site, Sina Weibo.

Chinese Internet companies police their own content, The Wall  Street Journal explains, and Sina’s team of “editors” are at the heart of the world’s largest effort to control social media. The speed is astonishing considering that 70,000 messages are posted per minute on average and the entire process can’t possibly be fully automated.

The study authors, one independent researcher and four American computer scientists, tracked the fate of 2.38 million Weibo posts published between July and September 2012. The findings:

  • Deletions happen most heavily in the first hour
  • 5% of deletions happened in the first 8 minutes and within 30 minutes, 30% of deletions were finished
  • 90% of deletions happen within the first 24 hours
  • 82% of deleted messages were reposts of earlier messages
  • Reposts are tracked down and deleted within 5 minutes
  • 300 of the 3500 accounts tracked were deleted when a user repeatedly posted sensitive content

This study also laid out some possible approaches. Censors probably refer to lists of sensitive terms and follow posters likely to say sensitive things. Most deleted posts contain code words to evade automatic keyword filtering; but as censors uncover fresh code words, they can use keyword searches to go back and delete them.

Censorship happens 24-hours a day, but there’s a lull in the early morning hours and when the news comes on at 7pm.

Previous work by the same team found that: “starting from the point where censorship begins, the frequency of the topic drops dramatically.”

But as the BBC reports: if Weibo had insufficient controls, the government may take action; if their controls were too rigid, users would abandon them for their competitors.

The work [pdf] is available at arXiv.

[Via WSJ, BBC]

amnesty international yahoo internet censorship in china

Internet Censorship in China: The result of searching for Amnesty International website from Yahoo China. (Brad T./China Gaze)

amnesty international yahoo india internet censorship in china

The result of searching for Amnesty International from Yahoo India. (Brad T./China Gaze)

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