The republic of China has a variety of laws concerning Internet censorship. The censorship does not apply to Hong Kong or Macau though since are special entities recognized by the international treaty with independent judicial power. The laws of free flow restriction do not all apply to them as well.
This effort the government has made to delete online opinion follows series of large anti-corruption protesta, ethnic riots and views agains pollution which were organized or made public through the internet. The size of the internet police is thought to be around 50.000. Critical comments appearing on blogs or other websited are often erased within minutes.
This Internet free flow repression is more advanced in China than in any other country in the world. Authorities do not only block websites. They also monitor what individuals access on the Internet. The country has the largest number of cyber dissidents in the world. Most of them are guilty for opposing the government, signing online petitions, having opinion on the end of corruption etc.
One example of such is Liu Shaokun, a teacher that was sentenced for „inciting a disturbance. He took photos of collapsed schools and posted online in 2008.
Another example from 2008 is Huang Qu, who was arrested for illegally possessing state secrets. He apparently dared to speak with foreign press about the horror of the lost children in the collapsed schools. Well, he did also post information on his website about it, but still I think imprisonment isn´t what he deserved.
At least 18.000 websites are blocked from within the mainland of China. Out of the top 100 global websites used in everyday life for most people, twelve of them are blocked in the country. In 2009, Facebook and Twitter were blocked, it is presumed because of containing things like political commentary.