(Newser) – A surveillance device that "tricks" cellphones into revealing their location has been a civil rights concern since it debuted. Now, for the first time, a federal judge agrees that using such a tool to ID a suspect's home without a warrant is an "unreasonable" violation of the man's rights, Reuters reports. US District Judge William Pauley ruled Tuesday the DEA shouldn't have used the "stingray" to find Raymond Lambis' NYC apartment during a drug-trafficking probe and, therefore, that the narcotics and drug-related items found at his home can't be used as evidence. "Absent a search warrant, the government may not turn a citizen's cellphone into a tracking device," Pauley wrote in his decision. The charge against Lambis happened just before a September Justice Department mandate that now requires a warrant "supported by probable cause before using a cell-site simulator," the New York Times notes. The stingray mimics cellphone towers and fools phones into transmitting pings to the fake tower, allowing authorities to track where the pings are coming from.

In Lambis' case, the DEA had a warrant for numbers called from a phone suspected in the drug investigation, as well as for records of the cellphone towers that phone was hooking up to. But the agency went a step further and used the stingray, finding an apartment building (and then Lambis' apartment) where the pings were especially strong—a step not covered by the original warrant, which led Pauley to insinuate the DEA had simply been lazy in not acquiring a second warrant, the Register notes. Lambis concedes he consented to the search of his bedroom, where the evidence was found, but he says in a court filing that's only because he didn't want his family's entire home "trashed" by a search if he didn't acquiesce, Ars Technica reports. "A federal court has finally held the authorities to account," a move that "strongly reinforces the strength of our constitutional privacy rights in the digital age," a staff lawyer for the ACLU's Speech, Privacy, and Technology Project tells the Times. Lambis' lawyer says he's not sure if his client's conspiracy charge will be dismissed. (Read more cellphones stories.)

