According to CNN, some malls in the US rolled out a new technology on Black Friday that allows retailers to track customers' cell phone signals while they're shopping. The technology is already being used in Europe and Australia, and it was scheduled to be tried out in two malls in California and Virginia. That was until Senator Chuck Schumer put a stop to it.

The "footpath technology" was developed by a British company called Path Intelligence—it tracks customers as they shop by monitoring their cellphone signals. Retail analysts told CNN that this shouldn't pose a huge privacy risk to shoppers, because cell phone companies fiercely guard the information that identifies the cell phone owner. But Schumer isn't so convinced.

His office wants Path Intelligence to get shoppers' explicit consent before it tracks their movements. This would be especially important if large retailers such as J.C. Penney and Home Depot, who are reportedly considering the technology, sign up for it.

The ACLU recently wrote to the CEOs of the nation’s major cell phone providers asking that they stop routinely collecting and storing data on their customers’ daily movements. You can sign their petition here. And if you want to check out more info about metadata, "inadvertent information sharing," and how to avoid being tracked via your cell phone, check out this site.