China's internet is not exactly famous for its freedom, but it takes a lot of effort to keep it tied down. Folks have done math to suggest there are thousands of government employees censoring China's Twitter-clone Weibo alone. Now the Beijing News is pegging that total at more like two million.
According to the Beijing News, not all of these people—rather amusingly called "internet opinion analysts"—are actively censoring web content. Instead they are trawling social media for troubling entries that are indexed and collated and then passed on to a presumably smaller group of actual decision-makers. All of these folks are apparently on the government's payroll.
According to the BBC's translation of the Beijing News article:
[Analysts] strictly to gather and analyse public opinions on microblog sites and compile reports for decision-makers. ... [An analyst] sits in front of a PC every day, and opening up an application, he types in key words which are specified by clients. He then monitors negative opinions related to the clients, and gathers (them) and compile reports and send them to the clients.
And it makes sense you'd need a veritable army of watchful eyes to keep that internet squeaky clean. Weibo alone has some 500 million users and 100 million messages daily.