Scientists in Germany have demonstrated a startling new form of surveillance: identifying people using nothing more than ordinary WiFi signals. By analyzing how radio waves bounce around a room, researchers can effectively “see” and recognize individuals — even if they are not carrying a device and even if their phone is turned off.
The imaging argument is just using 2.4GHz as a distance sensing radar, then using the normal transmitted wifi signal as the sender. In order to get the kind of image in the article’s illustration, they’d have to “beam sweep” the room, something that cell towers only do to a very limited degree (not nearly enough resolution to distinguish a FedEx truck from a mini-bus of similar size), and home WiFi barely do at all (I think some home wifi may do a little beam steering, but again, with nothing like that resolution shown.)
So, if the spies wanted to create a special (super costly) WiFi access point, it could “look like ordinary wifi” to an unsophisticated signal sniffer, but get these kinds of images. It also would be outrageously expensive as compared to an ordinary access point… unless they mass produce them…