The Police Are Tracking Everyone By Using Google Warrants

Detectives in the Raleigh, NC Police Department convinced a Wake County Judge to issue a probable cause order, compelling Google "to hand over account identifiers on every single cell phone that crossed the digital cordon [around a crime scene] during certain times". Raleigh police used search warrants to demand Google accounts not of specific suspects, but from any mobile devices that veered too close to the scene of a crime..." These warrants also prevent the technology giant [Google] from disclosing information about the searches for months, not just to potential suspects, but to any users swept up in the search.

Users can switch off location tracking to prevent the device from pinging GPS satellites. But if your phone is on a cellular network or connected to Wi-Fi, the device is still transmitting its coordinates to third parties, even if those coordinates are less accurate than GPS.