Cellphone users have a reasonable expectation of privacy of their cellphone location information, and law enforcement must obtain a search warrant before accessing that information, the Supreme Court of New Jersey ruled Thursday.

According to IDG News Service and PC World, when people disclose to phone companies or other service providers to use their services, they are not promoting the release of personal information to others, the ruling says.

Federal courts have been divided on the issue of cellphone tracking by law enforcement, but the New Jersey Constitution has offered greater protection to New Jersey residents.

The trial court found that defendant Thomas Earls, wanted for burglary and receiving stolen property, had a reasonable expectation of privacy under state law, and the police should have obtained a warrant to track him through cell-tower information. The court, however, admitted the evidence under an emergency aid exception to the warrant requirement.

The New Jersey decision is the first to establish a constitutional right in location data since the U.S. Supreme Court decided in United States v. Jones, a GPS-tracking case in which several justices expressed concern about the collection of location data, the article reports.

The court decided, however, that its ruling only applies to the Earls case and to future cases. The warrant requirement will take effect in 30 days from Thursday’s ruling to provide adequate time to the state’s attorney general to circulate guidance to state and local law enforcement officials.