CNN has uncovered exclusive new information about what is allegedly happening at the CIA, in the wake of the deadly Benghazi terror attack. Four Americans, including Ambassador Christopher Stevens, were killed in the assault by armed militants last September 11 in eastern Libya. Sources now tell CNN dozens of people working for the CIA were on the ground that night, and that the agency is going to great lengths to make sure whatever it was doing, remains a secret. CNN has learned the CIA is involved in what one source calls an unprecedented attempt to keep the spy agency's Benghazi...