If you run a bar, restaurant or other public gathering place it is time to put signs on the door and enforcement in your venue......
.....Let's make my point-of-view clear because anyone can download an app that will look for these devices in their proximity and can thus detect them, since they have to have an RF connection running in order to work: If I find one in your business and you have no policy on the door and aren't ejecting people and trespassing them for being there with them I'm gone and will never come back. No second chances, no ifs, ands, buts or maybes.
I don't care what the excuse is; I do not consent to being recorded on a blanket basis and that data used and no, I do not believe for one second that it will only be constrained to the person who has the device in terms of impact. It never has been thus far and never will be because we have simps in our government who will not put executives in prison for abusing said data and we also do not have real Americans who will cut off the heads of people who do so whether in government or the private sector.