For decades before Edward Snowden revealed the mass of secrets about National Security Agency activities, the most damaging revelations of American secrets probably came from Navy personnel, uniformed and civilian. These included the highly damaging revelations about U.S. military communications and the Navy’s Sound Surveillance System sold to the Soviets by John A. Walker and Jerry Whitworth; the sale to the Soviets of details of U.S. tapping of underwater cables by Ronald Pelton; and the sale of several thousand highly classified documents to the Israelis by Jonathan Pollard. And there were several others.
Subsequently, the Navy Department has been extremely careful about keeping secrets. Indeed, their efforts in many cases border on the absurd. For example, in the late 1950s the Navy acquired 12 P2V-3C Neptune aircraft for the carrier strike role. They were discarded within a few years—some 60 years ago. But when information was requested on the type of engines in the aircraft, that data was considered classified although the aircraft, their nuclear weapons—and engines—have been gone for many decades.