A federal judge in New York ruled that the use of a StingRay device without a warrant violates Fourth Amendment protections against unreasonable searches and seizures.

U.S. District Judge William H. Pauley III for the Southern District of New York threw out evidence that the Drug Enforcement Administration obtained in a drug trafficking investigation through the use of a StingRay device, also known as a cellsite simulator. The devices mimic wireless cell towers and allow law enforcement to intercept mobile calls, text messages and email messages.

The ruling is the first case in which a federal judge ruled that use of a StingRay device requires a warrant, said an attorney the Electronic Frontier Foundation. "It is also the first case in which a federal judge suppressed evidence" that was obtained a result of a StingRay device, Jennifer Lynch, senior staff attorney at EFF, told SCMagazine.com.

"Absent a search warrant, the Government may not turn a citizen's cell phone into a tracking device," Judge Pauley wrote in the 14-page decision. The ruling referred to the Justice Department's decision in September 2015 to issue new guidelines limiting the use of the devices: "Perhaps recognizing this, the Department of Justice changed its internal policies, and now requires government agents to obtain a warrant before utilizing a cellsite simulator."

Lynch does not expect prosecutors would seek an appeal. "I don't think the government has an incentive to appeal this case," she told SCMagazine.com, noting the revised guidelines the Justice Department's and the Department of Homeland Security.