In 2016, Gov. Bruce Rauner signed a bill banning the use of “stingrays” to track the location of phones and sweep up electronic communications without a warrant in most situations. The new law will not only protect privacy in Illinois, but will also hinder one aspect of the federal surveillance state.

Sen. Daniel Biss (D-Skokie) introduced Senate Bill 2343 (SB2343) on Jan. 28. The new law will help block the use of cell site simulators, known as “stingrays.” These devices essentially spoof cell phone towers, tricking any device within range into connecting to the stingray instead of the tower, allowing law enforcement to sweep up communications content, as well as locate and track the person in possession of a specific phone or other electronic device.

The new law prohibits the use of stingrays except to locate or track the location of a communications device or to identify a communications device. That means law enforcement cannot listen in on conversations using cell site simulators under any circumstances.

The House passed SB2343 115-0. The Senate approved the measure 57-0. With Rauner’s signature, the bill will go into effect on Jan. 1, 2017.

The legislation stipulates that before deploying a stingray device for location tracking, law enforcement agencies must get a warrant, with only a few exceptions. Warrantless use of these devices will only be allowed in certain specific emergency situations.

Under the law, if a court finds by a preponderance of the evidence that a law enforcement agency used a cell site simulator to gather information in violation of the limits in the act, then the information is presumed to be inadmissible in any judicial or administrative proceeding.

An amendment approved by the Judiciary Committee strengthened the bill, requiring police destroy any information gathered on non-targeted devices within 24 hours if the stingray was used to track or locate an known device, and 72 hours if used to track or locate an unknown device.