https://motherboard.vice.com/en_us/article/qvqgnd/sprint-stop-selling-location-data-tmobile-att-microbilt-zumigo

Last week, Motherboard revealed that AT&T, T-Mobile, and Sprint had been selling their customers’ real-time location data that ultimately ended up in the hands of bounty hunters and people unauthorized to handle it. Motherboard found this by purchasing the capability to geolocate a phone for $300 on the black market. In response, AT&T and T-Mobile said they were stopping all sales of location data to third parties.

Nearly a week later Sprint has committed to doing the same, in a statement to Motherboard.