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.
Yes, but 90% of ISP supplied modems around the world are modem + router + WiFi access point with a unified firmware.
You also can’t take the antennas off of those and they are required in order to receive internet.
Yes you can use your own router (I have a Unifi cloud gateway ultra myself and one access point in the middle of the house), but that doesn’t mean that disabling the WiFi on the ISP web-software bullshit actually disables the WiFi and doesn’t just hide the SSID and make it un-connectable and still use it for this kind of thing and identifying nearby devices.
It also doesn’t mean that all the routers themselves like my Unifi aren’t using the access points to do the exact same thing (or will in the future). The only way you can actually control that is with openwrt or similar.