According to Chinese state media, the country hires two million people to run and monitor its "Great Firewall".
Beijing News has reported that many employees are performing keyword searches and checking tens of millions of messages being posted each day.
The number of employees highlights just how low tech and human intensive the operations are.
Even then, staff are unable to prevent comments that are deemed by the government to be undesirable from being published and reposted.
The "web police" are hired by the government's propaganda arm, as well as by commercial sites.
China has more than 500 million internet users, making it the world's largest online population.
If a western country wanted to set up a similar operation it would have its work cut out to justify it.
According to our estimates, if David Cameron wanted to establish a "great firewall of Britain" he would have to hire roughly 210,000 people to keep up. Of course, British labour is not cheap, so it might be worth considering outsourcing such an operation to China.