With the new technologies, everybody can have access to information. In China, the government settled a censorship of the principal new social media, and a control over other media in the 1990's
The first policy they took was in 1996 Temporary Regulation for the Management of Computer Information Network International Connection passed during the 42nd standing convention of the state counsil in January 1993, definitely published in 1996 said that all internet providers must have a certification, and that "No units or individual are allowed to establish direct international connexion by themselves all direct linkage with the Internet must go through ChinaNet, BGNet, CERNet or CSTNet.
The second one is called Ordinance for Security Protection of Computer Information System. Published in 1994, the ordinance says that it's the ministry of Public Security which in charge of internet regulation in China, it can investigate on suspicious connexion. The ordinance also has some specified measures:
In 1999, The community basic law said: " Citizens in the community must not talk or behave in violation of all regulations issued by ChinaNet. (…) Those who disseminate obscene pornographic and anti-governmental speeches and opinions will have their user accounts suspended temporarily or deleted permanently in serious occasions"
Source: http://www.ijclp.net/files/ijclp_web-doc_1-4-2000.pdf
In january of this year, the Wall Street journal reported that Chinese government will use a "smarter and stricter" filter in a way to improve the blockage of the principal american services like Facebook or Google. They also announce the hardening of the anti-VPN system (a VPN is a software that allows you to go on web site censured by China like youtube, Facebook, google, twitter, and also to have access to all resources that are censored like the Tian'anmen articles, or Tibetans events).
The chinese government provide a new filter to create a parallel chinese internet system also to protect her companies from the biggest competitors.
Read the article: http://www.wsj.com/articles/chinas-great-firewall-gets-taller-1422607143