WASHINGTON (AP) - When you shop, does your smartphone spy on you? And if it does, should you care?
A growing numbers of retailers are using mobile-based technology to keep tabs on shoppers when they make their way through some malls and stores.
The key to the tracking is the phone's MAC address - and this Mac has nothing to do with an Apple computer. It's a 12-character set of letters and numbers that acts like a vehicle identification number for your mobile device. It isn't linked to personal information - but it does single out your particular phone or tablet.
Retailers can use the number to see where in a store you might spend the most time - or what stores in a mall you're visiting.
Stores and malls say you shouldn't worry your privacy is being invaded.
But consumer advocates say shoppers should be told their phones are being observed - even if the retailers say shoppers themselves aren't - and that customers should be able to opt out of such surveillance.