A study published by researchers at Carnegie Mellon University last year analyzed 56 million messages from Sina Weibo. That study revealed that the location a person posts from can affect the chances of that post being censored. Approximately half of all posts from Tibet and the neighboring region of Qinghai that used known sensitive words were deleted, while just over 12 percent of posts from Beijing and Shanghai using terms from the list were censored.

Social Media Censorship Offers Clues to China’s Plans" [MIT Tech Review]