The trackers work by mimicking cell phone towers, forcing phones in the area to ping them. Law enforcers can use this data to track and pinpoint a specific phone's locations. The Stingray can even flash firmware to a suspect's phone with a little more effort, turning the device into an audio bug.

This ruling marks the first time a federal judge has suppressed evidence found thanks to the use of stingrays. In a statement to Reuters, American Civil Liberties Union attorney Nathan Freed Wessler said: "This opinion strongly reinforces the strength of our constitutional privacy rights in the digital age."

The Justice Department changed its internal policies last September, with agents needing to obtain a warrant before using the Stingray. Lambis' lawyer noted that occurred a week after his client was charged, adding that it was unclear if the drug case against Lambis would now be dismissed.