Echoes of the Cold War days , when microphones hidden in foreign embassies were used to analyze the key sounds from traditional typewriters. By all accounts , this method did not work for "golf ball " electric typewriters .... which was great news for IBM , back in the day.
Your smartwatch may be revealing your card’s PIN code http://www.welivesecurity.com/2016/01/12/smartwatch-may-revealing-cards-pin-code/ Luckily I wear my watch on left hand and use right hand to type in my PIN
