Once you have this data, you can correlate it with records of purchases to link a given phone to a given credit card number. I'm guessing it would take just two or three purchases at the mall to be able to do a match with high confidence.
But we all know retailers care too much about their customers' privacy to pool that kind of information, so there's really nothing to worry about. And anyway, the fact people are reading the little signs and then continuing to shop without turning off their phones is a pretty clear indication that they're opting into this kind of data collection anyway.
But we all know retailers care too much about their customers' privacy to pool that kind of information, so there's really nothing to worry about. And anyway, the fact people are reading the little signs and then continuing to shop without turning off their phones is a pretty clear indication that they're opting into this kind of data collection anyway.