Google has signalled, in the strongest possible manner, that it will be pulling out of China unless something is done to address censorship of searches. It has also accused China of launching a "highly sophisticated and targeted attack" on the Google corporate infrastructure, along with another twenty large companies from a range of business sectors in the US.

Such attacks are nothing new, just last year the Pentagon was allegedly subject to a successful hacking attack with details of the F35 Lightning II, also known as the Joint Strike Fighter and the most expensive jet fighter ever, the target.

However, this time the worrying implication is that human beings were the target. Google says it has evidence to suggest that "a primary goal of the attackers was accessing the Gmail accounts of Chinese human rights activists".

David Drummond, Chief Legal Officer at Google, say that the company has discovered that the accounts of dozens of users based in China, Europe and the US, who are advocates of human rights in China "appear to have been routinely accessed by third parties. These accounts have not been accessed through any security breach at Google, but most likely via phishing scams or malware placed on the users' computers".

It is unusual for companies to go public with this kind of information, often for fear of damaging the brand or scaring users into thinking that security is not up to scratch, and that's without even mentioning the political row such accusations will undoubtedly cause. So what was Google thinking?

According to Drummond the human rights implications played a part as did a "global debate about freedom of speech" and he explains that when Google launched a China based operation in January 2006 it did so "in the belief that the benefits of increased access to information for people in China and a more open Internet outweighed our discomfort in agreeing to censor some results". The cyber-attack on Google combined with further attempts to limit free speech online over the last year have apparently made Google change its mind.

"We have decided we are no longer willing to continue censoring our results on Google.cn" Drummond says "and so over the next few weeks we will be discussing with the Chinese government the basis on which we could operate an unfiltered search engine within the law, if at all. We recognize that this may well mean having to shut down Google.cn, and potentially our offices in China".