Last week we wrote about China's blockade of most major social networks and search engines during the anniversary of the Tiananmen Massacre on 4th of June. Now, the Chinese authorities want to take it a step further, ordering that all PCs sold in the country, starting July 1, must come with software that blocks certain websites.

According to the Chinese government, who haven't yet gone public with the announcement, but have warned PC makers about the deadline, this measure's aim is to protect the Chinese from harmful content, primarily pornography. But since this same government has blocked sites like Twitter, YouTube, MySpace and Bing, it's quite possible that this software's primary aim is adding another layer of censorship over the existing Great Firewall.

The Chinese authorities have, however, taken a somewhat lax approach - for now. According to the WSJ, the software, whose Chinese name is "Green Dam-Youth Escort" needn't be pre-installed on the PCs; it may simply come in the form of a CD, and the users can choose whether they want to install it or not. The software is designed in such a way that it allows transferring of user's private information, as well as blocking sites other than pornography; according to software's developer, Jinhui Computer System Engineering Co, it would have no reason to do so. It doesn't sound very convincing, and given a choice, I'd definitely skip it; it's unclear, however, whether the authorities plan to somehow pressure users into installing the software.

There's always hope that the PC makers will try to resist these claims from the Chinese authorities, but it's hard to imagine them saying no, given the importance of the Chinese market. Furthermore, as we've seen in this latest blockade, there's always a technical workaround for these types of censorship attempts. However, if Chinese censors had control of what happens on user computers locally, as well as being able to block certain online destinations, it would make it much harder for users to circumvent such measures.