Triggerfish devices — often referred to as Stingrays — mimic cellphone towers, allowing them to pinpoint a phone's location, sometimes even before it makes a call or text. It is not clear exactly what information other than location that law enforcement gleaned from its use of a Stingray targeting Cohen.

What is triggerfish tracking?

Triggerfish describes a technology of cell phone interception and surveillance using a mobile cellular base station (microcell or picocell). The devices are also known as cell-site simulators or digital analyzers.

What do police use to track cell phones?

Mass cellphone surveillance

StingRays are used by law enforcement agencies to track people's movements, and intercept and record conversations, names, phone numbers and text messages from mobile phones. Their use entails the monitoring and collection of data from all mobile phones within a target area.