Soviets embarrass US with eavesdropping scandal
During the Cold War, the United States and the Soviet Union competed fiercely in the field of intelligence. the Soviet intelligence agency invented a type of microphone that does not require electricity, then disguised it as the national emblem of the United States and sent it to the US ambassador.
This microphone was hung on the wall of the US embassy, and everything the US ambassador said was always heard by Soviet agents. This eavesdropping lasted for 7 years, with 4 ambassadors and many renovations to the rooms, but this national emblem was never replaced.
It was not until British agents accidentally heard the American voice while eavesdropping that the matter was finally exposed. This eavesdropping scandal dealt a heavy blow to the United States, and also made the Soviet intelligence capabilities known to the world.