schwit1 quotes the International Business Times:
Both the CIA and the FBI declined to comment on reports saying the Chinese government killed or imprisoned 18 to 20 CIA sources from 2010 to 2012 and dismantled the agency’s spying operations in the country. It is described as one of the worst intelligence breaches in decades, current and former American officials told the New York Times.
Investigators were uncertain whether the breach was a result of a double agent within the CIA who had betrayed the U.S. or whether the Chinese had hacked the communications system used by the agency to be in contact with foreign sources. The Times reported Saturday citing former American officials from the final weeks of 2010 till the end of 2012, the Chinese killed up to 20 CIA sources.
Read more of this story at Slashdot.