Simona K In a new decision this week, the New Jersey Supreme Court ruled unanimously on Thursday that cops must get a warrant before tracking a cell phone’s location.
The ruling (PDF) only applies to residents of New Jersey, though it’s part of a growing body of case law that is shaping judicial approaches to the contentious issue. Montana recently became the first state in the US to pass a law requiring a warrant for cell phone tracking, less than a year after California’s governor vetoed a similar bill. In May 2012, the Florida Supreme Court ruled that law enforcement in the Sunshine State could seize a phone but that the cops need a warrant to actually search it. Meanwhile, the federal Fourth Circuit Court of Appeals is currently hearing a tracking case from Maryland suspects accused of armed robbery. Many of these cases—notably the Maryland case—rely on an established concept under federal law known as the “third-party doctrine.” This notion says that when a customer has voluntarily disclosed their own location to a mobile carrier (the “third party”) in the normal course of using a phone, then the customer no longer has a reasonable expectation of privacy of that information.
Therefore, says the doctrine, location data can be accessed by law enforcement without a warrant.