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.
From OPs linked article…
I can totally believe when it tracks a person it can tell when the same person walks by again later. But matching people with their actual identities would require a database of wifi scan data that simply doesn’t exist yet.
that’s a load bearing “yet”
Well in theory every tech possibility is a “yet”, but the way I read this it seems like a person or object’s interference pattern is particular to the local signal environment - not like a fingerprint a different system could recognize at the airport.