Cellphone carriers answered at least 1.1 million requests from law enforcement agencies seeking information on caller locations, text messages and other data for use in investigations last year, according to the carriers’ reports.

People have a reasonable expectation of privacy of their cellphone location information, the New Jersey Supreme Court rules. 

Stingray technology collects data from all cellphone use in an area in an effort to locate a potential suspect, but it also raises several key privacy issues, including Fourth Amendment restrictions against general warrants.