Your current device won’t do it but Wi-Fi can now identify people, and because it’s able to penetrate flesh it can identify people by skeleton so that it can’t be hidden by clothing. That’s separate from WhoFi being hard to identify peeler from gestures.[1]

This could be a future where your home devices sell what you look like to data harvesters who can then see you appear in shops which run the same scanners, even through walls where there’s no cameras, connecting back to the person who lives in your house near your future-vacuum cleaner. Even if you leave your phone and devices behind and pay in cash.

The historic privacy we had by virtue of things being physical started to fall slightly with writing and post which the government might intercept, further with telephone calls which the phone company could intercept, further with radio which could be hidden in one room listening, further with CCTV to CRT screen banks and no recording, further to purchases by credit card, then suddenly in the 90s to cellphone tracking and mass internet use, then the 2000s with Bluetooth beacon scanning and CCTV recording to disk and online purchases and unencrypted chat programs, faster in the 2010s where so many people upload their photo streams to Facebook which does face recognition on who is in photos and who is attending events, location tracking apps (all of them asking for that permission), to smartphones tracking location for live traffic and live store busyness ratings, and Hey Siri and Alexa and all the fitness tracker apps, and Ubers and video calling proxies through Microsoft and Google servers, cheap IoT CCTV left open to the world, car license plate tracking cameras…

“What is the concern” - is there really no concern?

[1] https://www.techspot.com/news/109975-wi-fi-can-accurately-id...