.....Even then, they wouldn't be able to "track" phones as it would be impossible to identify individual phones due to the encryption.....
Not wishing to disagree with someone far more knowledgeable on such things than I - however.....
I do know from experience that cell site analysis can and does provide specific information on specific mobiles, on legitimate legal request, such that vulnerable missing persons and similar can be located to searchable/viable ground areas.
Yes,
with the co-operation of the network operator you can locate mobiles, of course. Not to a particular isle in a department store, though, especially as inside a building GPS will not be available for phones so-equipped, so it'll be triangulation between cell sites kilometres apart.
There are also tracking services which will locate mobiles by the same means for the general public if the user of the phone answers an opt-in request. Again, it'll be a very coarse location, though.
My point is that it's not possible in the way described - a store autonomously tracking mobiles without the holder's consent based on detecting the signals they emit. I'd be a happy man if I'd managed to find a way to do it. I've been asked.
