On Thursday, July 18, the New Jersey Supreme Court ruled that police must first obtain a warrant to legally track data from cellphones in the state -- a decision that could have profound effects throughout the states and in federal courts, the New Jersey Star Ledger reported.

In issuing the ruling, the court sided with a man who was arrested in 2006 after police tracked him down using his cellphone data -- without a warrant.

“Today, cellphones can be pinpointed with great precision, but courts are not adept at calculating a person’s legitimate expectation of privacy with mathematical certainty,” according to a syllabus prepared by the Office of the Court. “What is clear is that cellphones are not meant to serve as tracking devices to locate their owners wherever they may be. No one buys a cellphone to share detailed information about their whereabouts with the police.” 

Some privacy proponents support the decision given the age of wide-ranging e-surveillance in which we currently live.

The new law does specify that no warrant is required during emergency situations.