Google’s decision to stop censoring google.cn, the company’s Chinese search engine comes after an exceptionally testing year, with the search engine’s operations coming under increasing public attack. Now the company’s unexpected announcement, that it will play by China’s rules no longer, reveals that its services and customers have come under a serious cyber attack endangering the security and privacy of its users.

Cynics may dismiss Google’s move as another example of business opportunism, but there’s more to it than that. There’s no doubt that Google did great damage to its reputation and credibility when it moved into China and sold some of its soul in the process. It always argued that it was trying to provide services that would improve lives and that it was prepared to submit to censorship rather than have no presence in China at all. But it was careful never to put itself in the same position as Yahoo!, forced to hand over information that might endanger its users.

Now that hackers have been accessing gmail accounts, that is exactly what has happened. Gmail is hugely popular amongst human rights activists both inside and outside China. Since it’s been revealed to be vulnerable, it’s quite a dilemma for its users and Google is going to have to work hard to restore confidence. On this basis, continuing to operate in China would have badly affected Google’s credibility.

Google has argued in its defence that it is governments rather than internet businesses that have to tackle censorship head on. But there is no doubt that Google’s acceptance of Chinese restrictions marked a dangerous acceptance of censorship. And human rights activists have argued that their presence in China not only legitimised censorship, but made it all the harder to campaign for freedom of expression.

Google’s bold decision to challenge China will not, on its own, change the system. China has a sophisticated bureaucracy of censorship in place that will remain unshaken. But it will have an impact on how other search engines and western businesses operate in China. Google’s decision to be transparent about censored search engine results has already had a direct impact on how other search engines operate in China. This could be the start of a whole new approach to dealing with regimes that censor.

Now that hacking has become a new tool in cyber wars, Google and others are going to have to work on a new front to safeguard freedom of expression.

It’s one of the biggest challenges now facing free speech online and political freedom.