Your ISP can theoretically use your home Wi-Fi router to track your movements.

This requires ancillary hardware that isn't present on wifi routers, and then it also requires wifi devices spread around the place to provide a signal source for human bodies to distort, and then it requires significant computational hardware that also isn't present in common home wifi routers.

Not to say that the general method can't be used for basic presence detection - Philips Hue ZigBee devices can use the variations in the background signal strength of ZigBee devices they can see around them to infer that someone is in a room, so they can switch lights on/off automatically. But it requires multiple devices in a room for it to work reliably and they need calibration as well.

Ditch the stationary routers. Buy a mobile router, tape it to the back of your phone and Bob's your uncle. /j

Orwell just turned in his grave.

Just because something is possible, doesn't mean that its in widespread use. TEMPEST has been around for decades, but that doesn't mean its actually practical to do so, especially when it comes to widespread implementation.

There are more important things to worry about.

i think this is related to this new app calle ruview and i think this is greatly exxagerated. not only you need a router, you need ESP32 nodes, plus you need to be relatively close to the router or have multiple router the bigger the location you're trying to scan. and i don't see how you isp would be able to do this from far away...

https://github.com/ruvnet/RuView

Oh man I'm glad I'm using an open source firewall with no WiFi and dedicated access points which have no access to the internet