At the 2016 Usenix conference, MIT's Computer Science and Artificial Intelligence Laboratory (CSAIL) presented a system called Chronos that could use wifi signals to detect the position of a person or object inside a room to within tens of centimetres. MIT claimed Chronos was 20 times more accurate than previous wifi-based tracking systems, 94% successful in detecting which room a person was in, and 97% accurate in determining if a customer was inside or outside a shop. The researchers hoped…