In 1945 a group of Russian schoolchildren visited the US embassy in Moscow and gifted them a wooden carving of the Great Seal of the US.
It took us 7 years to realize it was a listening device and they were spying on us.
www.spymuseum.org/exhibition-e....

The Great Seal
In 1945, a group of Soviet children visited the US Embassy in Moscow and gave the Ambassador a hand-carved Great Seal of the US. It stayed in his office…