One of the most ingenious bugs
ever developed was "The Thing,"
a listening device found in the
Great Seal that hung on the wall
of the U.S. Embassy in Moscow.
The seal, a gift from the
Soviets, had a tiny hole under
the eagle's beak to allow sounds
to reach the listening device.
Western experts were at first
baffled; the Thing had no batteries,
no power supply, and did not transmit radio signals, which
made it extremely difficult to detect. An expert from Britain's
MI5 finally solved the puzzle; the Thing was hit with
high-frequency radio waves from outside the embassy. Sound
absorbed by the microphone caused the antenna to vibrate,
causing modulations in radio waves beamed at it and reflected
back to a receiver.