Wow - position-sensing that can see through walls using your Wi-Fi router

https://youtu.be/0OdR8rRMz3I?si=zgOc_-IuUdFtrje9

Reflected radio waves can reveal a lot of information about things moving nearby. And, at a global scale, satellites can track ships that have "gone dark" for nefarious purposes. 

And this tech is simple and cheap - in this video, a single chip setup could read her heart rate and breathing through walls. 

https://youtu.be/oBDX_dPvq4A?si=O1TRbAuD-R2VUI-y