Retailers Tracking Your Cell Phone Signals

Stores try to follow your digital trail, but you can hide your movements.

Shoppers know there’s a trade-off involved in signing up for a retailer’s loyalty program or app: discounts and rewards in exchange for information about you and your buying habits. But simply browsing in a store with your cell phone in your pocket can be almost as revealing. That’s because when a phone scans for nearby wireless networks or Bluetooth signals, it emits a unique code, called a MAC (media access control) address. Companies can read the string of characters and zero in on your movements.

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Miriam Cross
Associate Editor, Kiplinger's Personal Finance
Miriam lived in Toronto, Canada, before joining Kiplinger's Personal Finance in November 2012. Prior to that, she freelanced as a fact-checker for several Canadian publications, including Reader's Digest Canada, Style at Home and Air Canada's enRoute. She received a BA from the University of Toronto with a major in English literature and completed a certificate in Magazine and Web Publishing at Ryerson University.