Reverse Engineering Weibo Censorship

Nieman Journalism Lab’s Andrew Phelps describes a new analysis of censorship on Sina Weibo by Chi-Chu Tschang. Tschang’s work explores when, why and how quickly weibo posts are removed, and offers a potentially useful tip for catching the censors off guard.

“We know that certain topics are censored from blogs hosted in China, Chinese search engines and Weibos,” Tschang writes in his paper. “But we don’t know where the line lies. Part of the reason is because the line is constantly moving ….”

Using the data visualization software Tableau, Tschang plotted … deleted weibos on a timeline, then superimposed politically sensitive events to provide context ….

And the best time to weibo something politically sensitive in China? After 11 o’clock on a Friday night, according to the data.

“Interestingly, deletion of Sina Weibo messages tend to hit a low on Saturdays,” Tschang wrote. “I’m not too sure why that is, except that maybe censors want to take time off on weekends as well.”

Another recent study of weibo deletions from Carnegie Mellon University found that geography also played a significant role: the deletion rate in Tibet—53%—was several times higher than in Beijing (12%) or Shanghai (11%).