One of the largest criticisms of the US intelligence community from the Robb-Silberman report is US counterespionage capability. As the linked article indicates:
The US has long had trouble with double agents. During the cold war, essentially every component of the US's national- security apparatus - with maybe the exception of the Coast Guard - was penetrated, experts say. Moles working for adversaries of the US stole closely guarded secrets, including details on nuclear weapons programs, cryptographic codes, and information on how the US spies on its adversaries.
Moreover, intelligence officials and experts say, this is an area where the US has never gained an advantage overseas, and it's becoming more difficult to operate in an ever-changing world.
For one thing, all 15 US intelligence agencies have ramped up their recruiting efforts - possibly opening the door to infiltrators - to support the government's policies in the war on terror. At the same time, the US has engaged in more information-sharing activities with allies - the coalition in Iraq, for example, and several other arrangements with foreign governments for strategic reasons.
Seems we haven't learned from the debacles of the 70s, 80s and 90s when penetrations of the CIA, FBI and NSA were exposed. See Edward Jay Epstein's excellent articles on Edwin Wilson (who claimed CIA membership while he ran his own operations), Vitaliy Yurchenko (a Soviet mole) and the Wen Ho Lee fiasco.