Hackers gained access to the Office of Personnel Management, which houses the personal data of all federal employees, and an official tells the New York Times that the hit was traced to China—though it's not clear whether Beijing sanctioned it. The March breach appeared to target the files of those who applied for top-secret security clearances before it was detected and blocked. A Homeland Security official confirmed the hack, noting that "at this time" the agency hadn't "identified any loss of personally identifiable information," though an emergency response team was assigned "to assess and mitigate any risks identified." (More hackers stories.)