From AP:
The company disclosed in a blog post that it had detected a "highly sophisticated and targeted attack on our corporate infrastructure originating from China." Further investigation revealed that "a primary goal of the attackers was accessing the Gmail accounts of Chinese human rights activists," Google's post said.
Google did not specifically accuse the Chinese government. But the company added that it is "no longer willing to continue censoring our results" on its Chinese search engine, as the government requires. Google says the decision could force it to shut down its Chinese site and its offices in the country.