It seems that the Kremlin is thinking of returning to typewriters instead of computers. In the 1970s, the Soviets developed a special sensor which could interpret the vibrations of windows in US Govt. buildings when typewriters were in use.
They could thus read the content of any secret memos in preparation.
Although silent, non-networked machines are still used to create certain documents, I’m told, today’s invention is simply a tapper device which bumps the window with a wide variety of frequencies and amplitudes whenever a keyboard of any kind is in use in a room. It might be possible to have it tap the window according to the content of a particularly rude but non-secret message, for example.
This should effectively scramble any possible eavesdropping, for both/any sides in a future cold war.
