I expect in the future, there will be calculated "secret leaks" to Wikileaks - who knows - these may be just that.
http://www.newyorker.com/arts/critics/atlarge/2010/05/10/100...
...in Peter Ustinov’s 1956 play, “Romanoff and Juliet.”... a crafty general is the head of a tiny European country being squabbled over by the United States and the Soviet Union, and is determined to play one off against the other. He tells the U.S. Ambassador that the Soviets have broken the Americans’ secret code. “We know they know our code,” the Ambassador, Moulsworth, replies, beaming. “We only give them things we want them to know.” The general pauses, during which, the play’s stage directions say, “he tries to make head or tail of this intelligence.” Then he crosses the street to the Russian Embassy, where he tells the Soviet Ambassador, Romanoff, “They know you know their code.” Romanoff is unfazed: “We have known for some time that they knew we knew their code. We have acted accordingly—by pretending to be duped.” The general returns to the American Embassy and confronts Moulsworth: “They know you know they know you know.” Moulsworth (genuinely alarmed): “What? Are you sure?”
...
At one point, the British discovered that a French officer in Algiers was spying for the Germans. They “turned” him, keeping him in place but feeding him a steady diet of false and misleading information. Then, before D Day—when the Allies were desperate to convince Germany that they would be invading the Calais sector in July—they used the French officer to tell the Germans that the real invasion would be in Normandy on June 5th, 6th, or 7th. The British theory was that using someone the Germans strongly suspected was a double agent to tell the truth was preferable to using someone the Germans didn’t realize was a double agent to tell a lie. Or perhaps there wasn’t any theory at all. Perhaps the spy game has such an inherent opacity that it doesn’t really matter what you tell your enemy so long as your enemy is aware that you are trying to tell him something.
This was just one layer of an onion.