It's a war between two Goliaths of the world, Google and China. In response to attacks on Google servers in China and government censorship there, the Web giant has shut its China website on 22 March. All users to Google.cn are now being redirected to Google's Hong Kong website.
Google's official blog said:
We also made clear that these attacks and the surveillance they uncovered—combined with attempts over the last year to further limit free speech on the web in China including the persistent blocking of websites such as Facebook, Twitter, YouTube, Google Docs and Blogger—had led us to conclude that we could no longer continue censoring our results on Google.cn.
So earlier today we stopped censoring our search services—Google Search, Google News, and Google Images—on Google.cn. Users visiting Google.cn are now being redirected to Google.com.hk, where we are offering uncensored search in simplified Chinese, specifically designed for users in mainland China and delivered via our servers in Hong Kong.
Google says it's aware that the Chinese government could at any time block access to its services. It has been caution enough to say that none of its China employees were responsible for the decision.
Finally, we would like to make clear that all these decisions have been driven and implemented by our executives in the United States, and that none of our employees in China can, or should, be held responsible for them.
Google has created a website where people can get the status of Google's services in China. So if you want to know if Google search is available in China today or a few days later, check the Web page that Google says will be updated daily. According to the latest information, its search, images, ads, news and Gmail services are currently accessible to Chinese users.