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.
Sure, but why bother?
Practically speaking, we all carry trackers in our pockets, attached to our phone number, email and social media. We already consent to giving away all that data, which basic ping triangulation also allows for fairly granular location tracking.
The wifi tracking method is helpful because it very granular in an otherwise opaque area. It tracks based on body size, who does what around the house, who specifically watched what on TV.
In that last comment, they said air traffic information. So think military aircraft movements.