Stingrays have been used on the ground and in the air by law enforcement for years but are highly controversial because they don’t just collect data from targeted phones; they collect data from any phone in the vicinity of a device. Stingray is the generic name for an electronic surveillance tool that simulates a cell phone tower in order to force mobile phones and other devices to connect to it instead of to a legitimate cell tower.
https://theintercept.com/2020/07/31/protests-surveillance-stingrays-dirtboxes-phone-tracking/
https://theintercept.com/2020/07/31/protests-surveillance-stingrays-dirtboxes-phone-tracking/