Chinese officials can effectively block all websites describing Tienanmen Square, but porn is almost completely eluding the Great Firewall, according to an interesting article on VNUnet.
Chinese porn sites raking in millions
Offshore operators of Chinese-language porn websites are making huge profits, Chinese government officials said earlier this week.
The article cites "high demand" for porn and how profitable it can be to fulfill it. But that leaves unclear why it's so much harder to block.
China uses a nationwide firewall to block access to a large number of websites that contain content which the government deems unsuitable. Many of these are political in nature, but also include sites dealing with religion and pornography.
It is not clear why this approach is failing to prove effective against the thousands of sites targeted in the latest crackdown.
A June 2005 article in Spectrum described how the Great Firewall works.
Sites are blocked, automatically and by hand, in two ways — by IP address or URL, and by keywords.
According to testing down back in 2005, the Chinese had, and still seem to have, a cautious strategy when it comes to keyword blocking. So it's easy for the authorities to block "Tienanmen Square," but they're not going to block, say, the word "sex." They can block "hot girls" but not every variation such as "hot girlz." And many sites will have only pictures or video, with no text at all to block. The government can block "sex.com" and "playboy.com" but not the 400,000 other sites with less explicit names.
Lastly, not only is it harder, but blocking porn may not have the same priority as anti-government politics or Falun Gong. The Chinese strategy seems to place a high priority to political, cultural, and economic stability. Those in control of the key branches of government may not be as socially conservative as they have been in the country's past, or as they are in some other countries around the world today.