Current Laws May Offer Little Shield Against Drones, Senators Are Told

The drones, or unmanned aerial systems, have already helped the police find missing people and county planners measure the growth of a landfill. But they could also be used by drug dealers, pedophiles and nosy neighbors, the witnesses and a senator said.

Surveillance by government is limited by the Fourth Amendment’s protection against unreasonable searches and seizures, and snooping by corporations and individuals is covered by privacy law and common law. But these were not written with drones in mind. The issue has taken on new urgency as the Federal Aviation Administration prepares to set forth rules for drones’ commercial use and as prices for the aircraft drop. Many states are considering legislation, but Congress is only beginning to consider the problem.

“There’s very little in American privacy law that would limit the use of drones for surveillance,” said one witness, Ryan Calo, an assistant professor at the University of Washington School of Law. “Drones drive down the cost of surveillance considerably. We worry that the incidence of surveillance will go up.”

But Benjamin Miller, of the sheriff’s office in Mesa County, Colo., who flies a two-pound, battery-powered six-rotor helicopter drone that he placed on the table in front of him, said his department had used a drone equipped with a thermal camera to investigate arson at a historic church, which helped firefighters identify hot spots and determine which direction the fire had traveled through the building. The sheriff’s office also used a drone for Mesa County’s annual survey of the landfill where it buries its garbage (to determine how quickly it is filling up), for about $200. The usual cost was nearly $10,000, Mr. Miller said.

The sheriff’s office operates its drones under a permit from the F.A.A., which requires that the aircraft stay under 400 feet and fly only in daylight. The rules are similar to the ones for radio-controlled model airplanes, which the drones resemble, although they have refinements like sophisticated autopilots, GPS navigation systems and stabilized cameras. Use of such drones by police departments and government agencies is still extremely limited. And commercial use — that is, a company flying a drone and being paid for it — is not yet legal.

The F.A.A. is to have rules in place for commercial use, including how to prevent collisions, by September 2015. But already there are thousands of drones in the nation’s skies.

Drones could be outfitted to read license plates and recognize faces, said Senator Charles E. Grassley of Iowa, the ranking Republican on the Judiciary Committee. “Just because the government may comply with the Constitution does not mean they should be able to constantly surveil, like Big Brother,” he said.

He warned that criminals could use drones because they were so inexpensive and capable, and that news reporters could use them in an intrusive way.

The hearing came the day after an unlikely pair on the House side, Representative Joe L. Barton, Republican of Texas, and Representative Edward J. Markey, Democrat of Massachusetts, introduced a bill to limit data-gathering by drones.

They said one problem was that the F.A.A., which would eventually be the licensing agency for those drones for which pilots needed licenses, had no jurisdiction in privacy, nor much expertise in the area. Mr. Barton’s and Mr. Markey’s bill would require licensed drone pilots to say publicly what their drones were doing and how the information would be used, among other protections. It is not yet clear which drones the F.A.A. will require licenses for, although people flying many of the smallest ones are unlikely to need them.

Some experts think the threat from the government is bigger than any from private use. “If it’s my neighbor that wants to snoop on me, he can’t put me in jail,” said Elizabeth Goitein, co-director of the Liberty and National Security program at the Brennan Center for Justice. “If Google or Amazon wants to use drone surveillance to figure out my market preferences, the worst thing that happens is I get marketed stuff I don’t need.”

Showing the public uneasiness over the new technology, one young protester at the hearing was led away by Capitol police after she stood up and declared, “Drones are responsible for the death of people in Pakistan, Afghanistan, Iraq, Somalia and Yemen!” Another protester held a sign that said, “1984.”

As Ms. Goitein observed, “The country can be divided into people who think this is horrifying and people who think this is neat.”