Hartford, Conn. (AP) – Law enforcement cellphone tracking devices are coming under scrutiny in at least eight states, with lawmakers introducing proposals ranging from warrant requirements to an outright ban.

Legislators are citing privacy and constitutional concerns, including Fourth Amendment search and seizure violations. The eight states include California, Connecticut, Mississippi, Missouri, New Hampshire, New York, Oregon and South Carolina.

The suitcase-size devices are widely known under a brand name, Stingray. They mimic cellphone towers and allow law enforcement to track the location of cellphones in real-time.

At least 13 states already have passed laws requiring police to get warrants to track cellphones in real time.

The American Civil Liberties Union says it has identified 70 law enforcement agencies in 23 states and the District of Columbia that own cell-site simulators.