AT&T was sued this week in the Northern District of California by customers alleging that AT&T sold their location data to data aggregators without their consent. The proposed class action suit was filed on behalf of all AT&T wireless customers from 2011 to date.

The suit alleges that AT&T sold customers’ location data to LocationSmart and Zumigo, third party service providers that provide location-based services to corporations without AT&T customers’ consent [view related post]. Wireless companies agreed to limit the sale of location data last year at the request of several members of Congress.

The suit alleges that AT&T failed to protect the customers’ confidentiality and that it has breached its duties to customers by disclosing location information to “thousands of third parties for years.” According to the suit, AT&T’s sharing of location based information to third parties was not transparent and customers were unaware that the information was being shared while they were using their phones.

The suit asks for monetary damages and an order to ban the sale of location based information.

AT&T denies the allegations, and has stated that it only shares location data with customers’ consent and that it stopped sharing location data with aggregators after it pledged to do so.