China’s government is to force computer manufacturers to equip all new machines with content filtering software. Officially it is to block material such as pornography, but there are fears it will be used as another method of silencing political critics.

The plan will extend the so-called ‘Great Firewall of China’, which operates on a network level, to individual desktops. Users will reportedly be allowed to remove the software, though it appears officials will be aware of which people choose to do this.

For those who don’t remove the software, their computers will be blocked from accessing sites listed on a database, which will be updated remotely. Individual users will be allowed to add and remove sites to and from the list, however, this will be a laborious process as the list itself will be kept secret.

The software, developed by a firm with links to the Chinese military and security agencies, is named Green Dam-Youth Escort. Green apparently refers to the idea of an internet free from ‘objectionable’ content. Firms which have examined the software say it could also allow the government to gather personal data on users, and that it may also make users more vulnerable to hacking attacks.

Jinhui Computer System Engineering says it was paid $3 million to produce the software which will be distributed without charge to all manufacturers. They must either install it on machines or include it on a bundled disc.

The move will cause a dilemma for overseas firms which supply China. They’ll have to decide between pulling out of what is potentially the world’s largest market, or actively complying in censorship.

Chinese censorship has been in the news recently after the government temporarily blocked access to sites including Twitter and Hotmail, apparently to limit discussion during the 20th anniversary of the Tiananmen Square protests.