In this Jan. 31, 2010 file photo, an unmanned U.S. Predator drone flies over Kandahar Air Field, southern Afghanistan, on a moon-lit night.
Illinois will regulate the use of drones by law enforcement under a bill signed into law by Gov. Pat Quinn.
The Chicago Democrat signed the measure Tuesday. Quinn spokesman Grant Klinzman said the governor signed the law -- SB1587 -- to protect people's right to privacy.
Drones are sophisticated, unmanned aircraft that authorities are considering for aerial surveillance. The law requires authorities to obtain a search warrant before using a drone to collect information.
Bill sponsor Democratic state Sen. Daniel Biss has said the law helps maintain a reasonable expectation of privacy. The American Civil Liberties Union praises the new law as appropriate and reasonable.
The legislation outlines a few exceptions, including when the Department of Homeland Security decides surveillance is needed to prevent a terrorist attack.
Drones are already flying in America's skies. But more widespread use is expected to begin in 2015 because of federal regulations.
The Illinois Senate passed the bill in April. The House followed suit in May.