According to Google, there has been a campaign to hack Gmail users' passwords in order to monitor their email accounts. 

Google informed however, that the company detected and disrupted this campaign which appeared to originate in Jinan, China.

Through the strength of our cloud-based security and abuse detection systems*, we recently uncovered a campaign to collect user passwords, likely through phishing. This campaign, which appears to originate from Jinan, China, affected what seem to be the personal Gmail accounts of hundreds of users including, among others, senior U.S. government officials, Chinese political activists, officials in several Asian countries (predominantly South Korea), military personnel and journalists, read Googleblog.