First learned about "The Thing" from the excellent book Spycraft: the secret history of the CIA's spytechs, from communism to Al-Qaeda by Robert Wallace and H.

First learned about "The Thing" from the excellent book Spycraft: the secret history of the CIA's spytechs, from communism to Al-Qaeda by Robert Wallace and H. Keith Morgan. The Thing was operating more than half a decade before it was detected, during which it listened in on 4 US ambassadors. And when they first found it they couldn't really figure out how it worked because it didn't have any electronics in it. Eventually Peter Wright at MI5 managed to reverse engineer its workings: "To operate the device, the NKVD aimed a continuous 800MHz radio signal at the seal from a listening post in the building across from Spaso House [the embassy]. The Thing's thin diaphragm at the top [...] vibrated with the sound of a voice. Those vibrations created modulations in the reflected radio signal that bounced back to the listening post. The Thing did not require power in the same way a mirror does not require power to reflect light. The radio transmitter and receiver code-named LOSS (or REINDEER by the Russian techs), were a marvel of signal processing considering the technology available at the time." chapter 12 p. 164 It's so cool to me that there is probably amazing tech out there right now, being used for all kinds of espionage operations which we will only find out about in 30 years or so. [0]: https://en.wikipedia.org/wiki/The_Thing_%28listening_device%29 https://en.wikipedia.org/wiki/The_Thing_%28listening_device%...