Hackers Steal Personal Information of US Security-Clearance Holders

The article says they were Chinese but offers no evidence:

The intrusion at the Office of Personnel Management was particularly disturbing because it oversees a system called e-QIP, in which federal employees applying for security clearances enter their most personal information, including financial data. Federal employees who have had security clearances for some time are often required to update their personal information through the website.

This is a big deal. If I were a government, trying to figure out who to target for blackmail, bribery, and other coercive tactics, this would be a nice database to have.