One of my all time favorites was a gotcha on us by the KGB during the early years of the cold war. I think it was either the head of NATO, or our highest ranking NATO official that was given a large wood carving of an Eagle - really a large wood shield about two to three feet in diameter [IIRC] with the elaborate carving on the face of it. It was presented as a personal "gift" from the Soviets along with a full serving of U.S. patriotic hype...I mean they really suckered us. This "gift" was mounted on the wall directly behind this official's desk in his private office - again, I'm thinking that this was the head of NATO but it may have been some other very high ranking military or intelligence official. The eye of the eagle was a microphone port. The internal circuitry was obviously well hidden, but the key was that it was only active if a KGB agent was across the street and pointing a microwave transmitter at the office window. The microwave energy would power the audio circuit and transmitter hidden in the shield. Since no local power source was present within the carving, and since the transmissions could be turned off by cutting the microwave source, it went undetected for many years. All bug scans of the time assumed that listening devices were powered with batteries so it never showed up during the regular sweeps. The damage was said to be immeasurable.