Senate Judiciary Committee Chairman Patrick Leahy (D-Vt.) said Wednesday that he is concerned about the growing use of drones by police to conduct surveillance.
"I think there could be a significant threat to the privacy and civil liberties of millions of Americans," Leahy said in a speech at Georgetown University Law Center.
He argued that sacrificing privacy will not make people safer.
Drones are cheaper to build and fly than helicopters, making them a cost-effective option for police departments looking to gain a bird's eye view of a scene. Domestic drones are now uncommon, but the Federal Aviation Administration has predicted that by the end of the decade, 30,000 commercial and government drones could be flying in U.S. skies.
More than a dozen police agencies around the country have already applied for licenses to operate drones.
Privacy groups are urging Congress to enact legislation that would set nationwide restrictions on how police can use drones.
They argue that drones allow for persistent tracking that would not be possible with manned aircraft.
Rep. Ted Poe (R-Texas) said on Tuesday that he has spoken with House Judiciary Committee Chairman Bob Goodlatte (R-Va.) about the privacy risks of domestic drones.
"I think that's on his agenda, to have some kind of drone legislation during the Congress," Poe said.
Last session, Poe authored the Preserving American Privacy Act, which would have only allowed police to use drones with a warrant and to investigate a felony.
He said he plans to reintroduce similar legislation this Congress with Rep. Zoe Lofgren (D-Calif.), another member of the Judiciary Committee.