antdude writes in with a story about two U.S. malls that plan on tracking shoppers' movements by monitoring the signals from their cell phones this Friday. "The management company of both malls, Forest City Commercial Management, says personal data is not being tracked. 'We won't be looking at singular shoppers,' said Stephanie Shriver-Engdahl, vice president of digital strategy for Forest City. 'The system monitors patterns of movement. We can see, like migrating birds, where people are going to.' Still, the company is preemptively notifying customers by hanging small signs around the shopping centers. Consumers can opt out by turning off their phones."