“[they] train a neural network to interpret the way radio WiFi signals bounce off a person’s body and translate it into the movement of 14 different key points on the body.” "Let’s say the police want to use such a device to see behind a wall"
▻https://motherboard.vice.com/amp/en_us/article/a3aaqp/mit-device-uses-wifi-to-see-through-walls-and-track-your-movements