The Espionage Act of 1917
The Reagan Administration effectively used the Espionage Act of 1917 to prosecute a leak - to the horror of the news media. It was a case that was instituted to make a point, and establish the law, and it did just that in spades.
In July 1984, Samuel Morrison - the grandson of the eminent naval historian with the same name - leaked three classified photos to Jane's Defense Weekly. The photos were of the Soviet Union's first nuclear-powered aircraft carrier, which had been taken by a U.S. spy satellite.
Although the photos compromised no national security secrets, and were not given to enemy agents, the Reagan Administration prosecuted the leak. That raised the question: Must the leaker have an evil purpose to be prosecuted?
The Administration argued that the answer was no. As with Britain's Official Secrets Acts, the leak of classified material alone was enough to trigger imprisonment for up to ten years and fines. And the United States Court of Appeals for the Fourth Circuit agreed. It held that the such a leak might be prompted by "the most laudable motives, or any motive at all," and it would still be a crime. As a result, Morrison went to jail.
The Espionage Act, though thrice amended since then, continues to criminalize leaks of classified information, regardless of the reason for the leak. Accordingly, the "two senior administration officials" who leaked the classified information of Mrs. Wilson's work at the CIA to Robert Novak (and, it seems, others) have committed a federal crime.