About fifty years ago. The Soviets did it to the US: https://www.cryptomuseum.com/covert/bugs/selectric/ https://www.cryptomuseum.com/covert/bugs/selectric/ h

About fifty years ago. The Soviets did it to the US: https://www.cryptomuseum.com/covert/bugs/selectric/ https://www.cryptomuseum.com/covert/bugs/selectric/ https://news.ycombinator.com/item?id=21947924 https://news.ycombinator.com/item?id=21947924