THE 500m people who use the internet in China have long been aware of the presence of the censors who watch their movements online and delete their more inflammatory posts. Now those monitors may have to get used to someone watching over their shoulders. Teams at Harvard and the University of Hong Kong have been using new software that allows them to watch the censoring of posts on Chinese social-media sites more closely than before. And now they have started to release some of their key findings. According to one report, a team of researchers at Harvard found that 13% of all social-media posts in China were censored. “The Chinese government made the decision to allow its people to have social media, but they also built a vast machine to monitor what is said,” says Gary King, a professor in the university’s government department and the report’s lead author.

Mr King and his team used programs developed by a company he co-founded, Crimson Hexagon Inc, to monitor activity surrounding 85 sensitive topics, ranging from last year’s protests in Inner Mongolia to Ai Weiwei, China’s best-known artist overseas, as well as governmental policies and other subjects that might conceivably spur mass protests. Their monitoring has been able to identify when posts bearing these terms appear and disappear—and with that, how long it takes for each to be taken down.

The team has built up a database comprising more than 11m posts that were made on 1,382 Chinese internet forums. Perhaps their most surprising result is that posts critical of the government are not rigorously censored. On the other hand, posts that have the purpose of getting people to assemble, potentially in protest, are swept from the internet within a matter of hours.

“We thought they were concerned with how they looked, but that’s not the case,” says Mr King. “Clearly the goal is actually to repress people gathering.”

Rebecca MacKinnon, the author of “Consent of the Networked: The Worldwide Struggle for Internet Freedom”, agrees. “The goal has never been total control. The goal is to keep the Chinese Communist Party in power,” she says. “Total, stifling, straitjacket control is not possible unless they want China to be North Korea, which they don’t.”

In contrast to the Harvard team’s approach, researchers at the University of Hong Kong have developed a program that concentrates solely on China’s most popular microblogging site, Sina Weibo. The program monitors the accounts of 300,000 users who each have more than 1,000 followers: “the most influential group”, according to King-wa Fu, an assistant professor and one of the developers of WeiboScope.

They found that by monitoring Sina Weibo’s account-holders’ profiles at different times of day they were able to witness the work of the censors almost in real time and to identify individually the posts that they disappeared. The researchers then examined the removed posts to try divining what had made them objectionable to the censors.

“What we are finding is a constantly morphing list of keywords, a cat-and-mouse contest between people and censors,” said Mr Fu.

These programs mean that, increasingly, researchers are able to create a more transparent picture of censorship in China—and to pinpoint the most sensitive topics at any given time. More intriguing perhaps, with a bit of luck and savvy researchers might be able to predict when something big is about to happen in a certain sector or to a certain individual.

When Mr King’s team analysed data connected to the Bo Xilai scandal, to the arrest of Ai Weiwei and to other recent censor-worthy news they found clear signals in retrospect: a noticeable ramping up of censorship related to those topics, days before the news broke.

Put simply, if these database-researchers happen to be looking in the right place, the censors might inadvertently become their best tipsters.

So far the teams have been focused on looking back on data regarding past events. Having reached their initial conclusions, they are ready to chase more elusive quarry. “Now we will watch going forwards,” says Mr King.

Censors beware: you are being watched.

(Picture credit: WeiboScope)