Kremlinism/Espionage

https://en.wikipedia.org/wiki/Leon_Theremin#Espionage

During his work at the sharashka, where he was put in charge of other workers, Theremin created the Buran eavesdropping system. A precursor to the modern laser microphone, it worked by using a low-power infrared beam from a distance to detect sound vibrations in glass windows.[2][42] Lavrentiy Beria, the head of the secret police organization NKVD (the predecessor of the KGB), used the Buran device to spy on the British, French and US embassies in Moscow.[42] According to Galeyev, Beria also spied on Stalin; Theremin kept some of the tapes in his flat. In 1947, Theremin was awarded the Stalin prize for inventing this advance in Soviet espionage technology.

Theremin invented another listening device called The Thing, hidden in a replica of the Great Seal of the United States carved in wood. In 1945, Soviet school children presented the concealed bug to the U.S. Ambassador as a "gesture of friendship" to the USSR's World War II ally. It hung in the ambassador’s residential office in Moscow and intercepted confidential conversations there during the first seven years of the Cold War, until it was accidentally discovered in 1952.