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.
If you’re technical you might like enjoy this article that explains how the tracking works. Basically the router can perform math on the interference created by objects moving around the room. It seems like this would have to be part of the router firmware, which doesn’t sound like a standard feature. But if it is, the fix would be to install modified firmware with that function disabled. The smoking gun will be if somebody gets into DMCA trouble for doing this.
New person in room detected, please drink verification can.
that’s not a sufficient fix when you are living very close to other households
A sufficient fix is not letting your wifi devices connect to your neighbor’s network so their router can detect you walking between it and them.
my devices don’t, but unless I misunderstood it it does not matter whether you are connected to the neighbor’s router
Wifi tracking uses measurements of the interference caused when objects pass between connected devices and a router. For your neighbors to track your movements their router would have to be connected to a device in your house, or maybe in the other neighbor’s house on the far side of your house, so when you walk around it interferes with that signal.