New Jersey Supreme Court
Chief Justice RABNER delivered the opinion of the Court.
Full Opinion: http://www.leagle.com/decision/In%20NJC ... v.%20EARLSAdvances in technology offer great benefits to society in many areas. At the same time, they can pose significant risks to individual privacy rights. This case highlights both principles as we consider recent strides in cell-phone technology. New improvements not only expand our ability to communicate with one another and access the Internet, but the cell phones we carry can also serve as powerful tracking devices able to pinpoint our movements with remarkable precision and accuracy.
In this appeal, we consider whether people have a constitutional right of privacy in cell-phone location information. Cell phones register or identify themselves with nearby cell towers every seven seconds. Cell providers collect data from those contacts, which allows carriers to locate cell phones on a real-time basis and to reconstruct a phone's movement from recorded data. Those developments, in turn, raise questions about the right to privacy in the location of one's cell phone.
Historically, the State Constitution has offered greater protection to New Jersey residents than the Fourth Amendment. Under settled New Jersey law, individuals do not lose their right to privacy simply because they have to give information to a third-party provider, like a phone company or bank, to get service. See State v. Reid, 194 N.J. 386, 399, 945 A.2d 26 (2008). In addition, New Jersey case law continues to be guided by whether the government has violated an individual's reasonable expectation of privacy.
Applying those principles here, we note that disclosure of cell-phone location information, which cell-phone users must provide to receive service, can reveal a great deal of personal information about an individual. With increasing accuracy, cell phones can now trace our daily movements and disclose not only where individuals are located at a point in time but also which shops, doctors, religious services, and political events they go to, and with whom they choose to associate. Yet people do not buy cell phones to serve as tracking devices or reasonably expect them to be used by the government in that way. We therefore find that individuals have a reasonable expectation of privacy in the location of their cell phones under the State Constitution.
We also recognize that cell-phone location information can be a powerful tool to fight crime. That data will still be available to law enforcement officers upon a showing of probable cause. To be clear, the police will be able to access cell-phone location data with a properly authorized search warrant. If the State can show that a recognized exception to the warrant requirement applies, such as exigent circumstances, then no warrant is needed.
Having a clear set of rules serves two key goals. It protects legitimate privacy interests and also gives guidance to law enforcement officials who carry out important public safety responsibilities. Because today's decision creates a new rule of law that would disrupt the administration of justice if applied retroactively, the rule will apply to this defendant and prospective cases only.
The issue before the Court arises in the case of a burglary investigation. In an effort to locate the target and his girlfriend, whose safety was in question, the police obtained cell-phone location information from T-Mobile on three occasions during the same evening — without first getting a court order or a warrant.
The trial court found that defendant had a reasonable expectation of privacy in his cell-phone location information but admitted the evidence under the emergency aid exception to the warrant requirement. The Appellate Division affirmed on different grounds. It concluded that defendant lacked a reasonable expectation of privacy in his cell-phone location information and that the police lawfully seized evidence in plain view. The panel had no reason to consider the emergency aid doctrine.
Because we find that cell-phone users have a reasonable expectation of privacy in their cell-phone location information, and that police must obtain a search warrant before accessing that information, we reverse the judgment of the Appellate Division. To determine whether the emergency aid doctrine or some other exception to the warrant requirement applies to the facts of this case, we remand the matter to the Appellate Division for further proceedings.