- Blocking specific IP addresses through a system firewalls and proxy servers, collectively called the Golden Shield,
- DNS poisoning and redirection (where attempts to connect to particular websites by name are blocked or redirected), and
- Packet filtering (where content passing over the network is monitored for keywords like "democracy" or "freedom").
Those blocked most often are dissident sites calling for Western-style democracy, pro-Taiwan and pro-Tibet sites, Western news agencies and other nations' government sites, and sites with explicit sexual content. In addition, human censors, estimated in number between 30,000 and 50,000, are said to routinely police online web portals, forums and blogs, taking down offending content as soon as it is posted.
Chinese officials have argued that its censorship practices are no different from those of other (including Western) governments that keep an eye on socially harmful content on the Internet. They also claim that nobody has been convicted for posting anti-government content online, though other sources disagree on this matter.
The government also keeps issuing new legislation frequently, leading some to suspect that some of the policies do not work as effectively as expected. While most people outside China tend to be critical of the censorship imposed by the Chinese Government, we should remember that most of the technology used to effect censorship - network hardware, software, and services such web portals and search engines - is supplied by Western (mostly US) corporations.