Illinois law reins in cellphone monitoring

SPRINGFIELD, Ill. — A new Illinois law limits how police can use devices that cast a wide net in gathering cellphone data — devices at the center of a lawsuit against the Chicago Police Department.

Gov. Bruce Rauner signed the legislation into law on Friday and drew immediate praise from civil libertarians.

The technology, a cell site simulator, is perhaps best known by the brand name Stingray. It gathers phone-usage data on targets of criminal investigations, but it also gathers data on other cellphones — hundreds or even thousands of them — in the area.

The new law requires police to delete the phone information of anyone who wasn’t an investigation target within 24 hours. It also prohibits police from accessing data for use in an investigation not authorized by a judge.

A dozen other states have adopted such regulations, and Congress is considering legislation that would strengthen federal guidelines already in place.

“Cell site simulator technology too powerful to remain unregulated,” Khadine Bennett, who is associate legislative director for the American Civil Liberties Union of Illinois, said in an emailed statement in which the group thanked the governor and Legislature for the new law.

“The federal government has adopted modest guidelines similar to those enacted today. If the restrictions are good enough for the FBI, they should be workable for local law enforcement in Illinois.”

The Illinois State Police has taken a neutral position on the law and the Chicago Police Department did not take a position.