Controversial software that screens out "offensive material" from the internet, better known as "Green Dam", has been shown to have security flaws that could lead to the computer being taken over by malicious hackers.

The government has mandated that the software be installed on every computer in the country, a move described by Chinese computer experts as a "large-scale disaster".

To make matters worse, it's reported that the software only runs on Windows and only filters Internet Explorer. As a result, anyone using a Mac, Linux, or even just installing Firefox, has no problems accessing whatever content they like.

The software works by assessing how much naked flesh there is on a page by trying to identify skin tones. The system doesn't work entirely smoothly. One commenter on the message board run by the company said:

"I went on the internet to check out some animal photos. A lovely little naked pig was sent onto the black list. Pitiful little pig!". Another said: "I was curious, so I looked up some photos of naked African women. Oh, they were not censored!".

The company's message board is currently "being upgraded" and offline.