As summarized by  Madeline Earp at CPJ , “A flurry of research on Weibo censorship underscores what we already know about the Chinese company Sina’s microblog service–with a few surprises thrown in. ”

Top 73 censored words from Weibo

Academics at MIT Harvard Carnegie Mellon University , and the University of Hong Kong  have been independently compiling data about when and why content is blocked on Weibo. Here are some interesting findings:


  • Where you are makes a difference: “The rate of message deletion is not uniform throughout the country, with messages originating in the outlying provinces of Tibet and Qinghai exhibiting much higher deletion rates than those from eastern areas like Beijing.” (Carnegie Mellon University )
  • But not if you’re outside China: “Censors are able to delete posts from any Weibo account, even if the user lives outside the mainland” according to the South China Morning Post‘s report on findings from the University of Hong Kong’s journalism school.
  • Researchers can salvage censored content: The University of Hong Kong’sWeiboScope  ”tracks the profiles of 300,000 Sina Weibo users who have more than 1,000 followers. The program downloads their posts throughout the day, and by comparing their profiles at different times, researchers can identify deleted posts,” according to the South China Morning Post.
  • They can also track sensitive terms over time: Most deleted topics in June were activist Chen Guangcheng, U.S. Ambassador to China Gary Locke, former Chongqing party secretary Bo Xilai, and activist Li Wangyang, who died in mysterious circumstances on June 6, the Post reported, citing WeiboScope research.
  • Censorship can be immediate, or it can take a while: The fastest a post was deleted on Sina Weibo was just over four minutes. The slowest? Over four months, according to MIT Sloan School MBA candidate Chi-Chu Tschang , as cited on Harvard’s Nieman Journalism Lab  website.
  • “Permission denied” = censorship:  Of course, Weibo users can delete their own posts. But MIT and Hong Kong researchers agreed that a “permission denied” message indicates previously available content has been censored.
  • Censors take the weekend off:  Deletion “tends to hit a low on Saturdays” Tschang wrote, according to the Nieman Lab

For all those researched above, they widely used data mining technologies by programming with APIs provided by Weibo services. Along with the development of censorship mechanism, such methods may not always be consistent and effective. We are seeking some new ways to make “censorship” research more intelligent along with our most recent Social Brain Framework. Stay tuned.