https://phys.org/news/2018-06-good-bad-tracking.html

LOCATIONS DISCLOSED WITHOUT CONSENT OR COURT ORDER

In a letter to AT&T president Randall Stephenson, Sen. Ron Wyden (D-OR) said that he "recently learned that Securus Technologies, a major provider of correction facility telephone services, purchases real-time location information from major wireless carriers and provides that information, via a self-service portal, to the government with nothing more than a pinky promise." Wyden also went after Verizon, T-Mobile and Sprint. So far, Verizon, AT&T and Sprint have announced that they will no longer provide this information to these third parties.