How China silenced its online critics

China has succeeded in neutralising the country's most free-flowing and important source of news and opinion, according to research that shows a dramatic drop in activity on the microblogging website Sina Weibo.

Research commissioned by The Daily Telegraph shows that the number of posts on the successful site, China's answer to Twitter, may have fallen by as much as 70% in the wake of an aggressive campaign by the Communist Party to intimidate influential users.

Once an important public space for news and opinion that censors struggled to contain, it seems to have been reduced to a wasteland of celebrity endorsements, government propaganda and corporate jingles.

At its peak, Weibo was indispensable to almost every young Chinese, generating huge fan bases for actresses such as Yao Chen (58million followers) and business gurus such as Kaifu Lee (51million).

In an attempt to reach out to the Chinese market, stars such as Tom Cruise, Brad Pitt and Emma Watson all joined Weibo, as did a number of politicians, including British Prime Minister David Cameron and Boris Johnson, the London mayor.

But the findings of the research will be a blow to those who hoped Weibo would weaken the Communist Party's monopoly on information.

Professor Qian Weining and researchers at the Institute for Data Science and Engineering at East China Normal University analysed a sample of 1.6million Weibo users from the start of 2011 to the end of last year.

They tracked the number of posts made each day, which gradually swelled to a peak in March 2012, when that sample group alone made a total of 83.8million posts.

But that was the month that the Communist Party struck its first major blow against Weibo, requiring users to register their real names with the service.

From that point, those wishing to criticise the party had to do so without the comforting blanket of anonymity, and users started to rein in their comments.

In the following months, the party tightened its censorship of the service, deleting the accounts of activists and instituting a "five-strikes-and-out rule", which suspended the accounts of anyone posting five "sensitive" tweets for 48 hours.

But Weibo remained resilient. It was still the only way for the Chinese public to air their grievances and absorb information that had not come from state media.

In June last year, the party changed tack. It began arresting hundreds of users posting "rumours" on Weibo.

In August, Charles Xue, an outspoken venture capitalist with 12million followers, was arrested for allegedly soliciting prostitutes. He was paraded on state television in what was seen as a warning to other prominent Weibo users.

Two weeks after his arrest, the daily number of tweets from the sample group halved.

The authorities had succeeded in terrifying users into submission. Prominent bloggers He Weifang, a liberal law professor, Zhang Lifan, a historian, and Liu Ou, an investigative journalist, either quit or were driven from the service.

"There are many reasons I chose to close my account," said He.

"First, many people I know have left. Also, I have been attacked a great deal and I am tired. And, finally, the influence of Weibo has not been as great as I expected. Since I switched off, life has been more calm and I can read more books."

Zuoxiao Zuzhou, a musician with 1.9million followers, said he had phased out Weibo.

"People are using it less and less to reveal the truth. Weibo's impact on the public will keep decreasing," he said.

In March 2012, there were almost 430000 people posting 40 times a day almost every day. By December last year, there were 114000, a fall of 73%.

Many of Weibo's former devotees have switched to WeChat, a Chinese version of WhatsApp. The mobile app enables users to message their friends privately.