Gov. Bruce Rauner signed legislation Friday requiring police forces in Illinois to get a court order before using surveillance equipment to covertly scan people's cellphone data.
The equipment in question, often called "Stingray," acts like a cellphone tower and is typically attached to police surveillance vehicles. It can collect data secretively from nearby cellular devices.
Under the new measure, police are prohibited from keeping data captured by the equipment if it comes from an individual not under investigation.
Also, the technology cannot be used "to block phone calls, drain a phone battery or intercept the content of phone calls, web browsing and text messages by police," according to the American Civil Liberties Union (ACLU) of Illinois.
"We are grateful that Governor Rauner has moved to enact this measure, protecting the privacy of everyone who uses a cell phone or smartphone," ACLU of Illinois Associate Legislative Director Khadine Bennett said in a statement Friday. "Given the prevalence of these devices and our reliance on the technology daily in today's society, cell site simulator technology [is] too powerful to remain unregulated. 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.
"We also thank State Senator Daniel Biss, State Representative Ann Williams and the overwhelming bipartisan majority in both houses of the legislature that approved this measure."