To be clear, this is using the same frequencies WiFi uses, but customized hardware and software to accomplish the task. Those frequency bands can of course penetrate walls. It's why we picked them for network connectivity.
It's a long jump from yet another method to detect things using EM radiation to plugging an AI into your WiFi router to spy on people.
Sure. WiFi is just using radio waves, and if the software is advanced enough, you could potentially use wifi signals as a form of radar to map things. Not sure how great the resolution could potentially be though.
The entire world is filled with so much information absolutely everywhere. Everything is constantly leaking it out, blasting it in every direction. One of the most worrying potential capabilities that could rapidly emerge in AI is collecting and finding patterns in this information.
Look at examples of side-channel attacks for computers, and then realize that AI has the potential to have side-channel attacks for... everything. It's pretty scary how much you can narrow down guesses when you have a few pieces of information. Using WiFi to learn about a physical space is just the surface.
There was a side channel attack recently where an off the shelf camera was able to extract a security key, just from watching micro fluctuations in the power led and modelling how those corresponded to specific computations being done ....
This whole universe is proving to be a rather difficult side channel to secure.
The way this supposedly works is that wifi waves can be used to detect bodies to such fidelity it can recreate a 3d model of the room and people. Thats your visualization.
But i came here for a more in depth explanation, take mine with a dose of salt.