"An investigation by Quartz has revealed that Android devices send cell tower location data to Google even if the user has disabled location services for apps in their device settings."

Cell tower observed location data being sent even if devices had been reset to factory default settings. Android devices with a cellular data or a wi-fi connection were seen to send the data to Google each time they came within range of a new cell tower, including devices with no SIM cards installed. Currently, there's no way for Android users to prevent their location data from being sent to Google.

Location data is highly sensitive personal data from which much can be inferred from a person’s life and lifestyle. Whatever the reason Google was experimenting with harvesting Android users’ location info, it’s another troubling instance of the company slurping up sensitive user data without making people explicitly aware it’s doing so.


Bibliography
TechCrunch
Natasha Lomas
https://techcrunch.com/2017/11/21/android-devices-seen-covertly-sending-location-data-to-google/