https://www.cnbc.com/2018/06/25/privacy-scotus-cell-data-carpenter-v-usa.html

The Supreme Court last week ruled that pulling cellular site records from a wireless carrier requires law enforcement to obtain a warrant, a potentially far-reaching decision for the telecom industry,

In ruling 5-4 on the side of Timothy Carpenter, who was convicted in 2013 of robbing Radio Shack and T-Mobile stores, the court determined that law enforcement officers illegally procured location data from his cell phone carriers. The government was able to get 12,898 location points tracking Carpenter over 127 days, with four of those hits putting Carpenter near sites where robberies had occurred.