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.)
IIUC they’d need gait data of the people to be identified. So if it’s someone you have a lot of video of, it’s potentially tractable.
Meta has this kind of data on a fuckton of humans; TikTok probably has it on the rest.
Jesus, we’re fucked