Léon Theremin
Theremin was put to work in a secret research and development laboratories in the Soviet Gulag labor camp system. Theremin created the "Buran" eavesdropping system which recorded conversations in French and American embassies by measuring the window glass vibrations using a low power infrared beam from a distance. Lavrentiy Beria, head of the KGB then used Buran to spy on US, British and French embassies.