The technology to convert wifi signals into the placement and identity of people is getting much better. Not by using their devices, just the waves bouncing of their bodies. (There’s nothing new to the pipeline as far as I can tell, we’re just starting to get into the accuracy ranges that make it easy/useful.)
Better to pollute the signal, maybe? They’re picking up on irregularities in it already (I guess), so why not add a light scramble. Maybe it can be done below any threshold to be noticeable, and you just place a box next to your router for it to work.