https://motherboard.vice.com/en_us/article/j5z74d/senators-harris-warner-wyden-fcc-investigate-att-sprint-tmobile-bounty-hunters

On Tuesday, Motherboard revealed that major American telcos T-Mobile, AT&T, and Sprint are selling customer location data of users in an unregulated market that trickles down to bounty hunters and people not authorized to handle such information. In our investigation, we purchased the real-time location of a cell phone from a bail industry source for $300, pinpointing it to a specific part of Queens, New York.

The issue potentially impacts hundreds of millions of cell phone users in the United States, with customers likely unaware that their location data is being sold and resold through multiple companies, with even the telcos sometimes having little idea where it ends up and how it is used.