Drones can help police departments find missing people, reconstruct traffic accidents and act as lookouts for SWAT teams. Real estate agents can have them film videos of properties and surrounding neighborhoods, offering clients a better-than-bird's-eye view though one that neighbors may not wish to have shared.
"Any legislation that restricts the use of this kind of capability to serve the public is putting the public at risk," said Steve Gitlin, vice president of AeroVironment, a leading maker of smaller drones.
Yet the virtues of drones can also make them dangerous, privacy advocates say. The low cost and ease of use may encourage police and others to conduct the kind of continuous or intrusive surveillance that might otherwise be impractical.
Drones can be equipped with high-powered cameras and listening devices, and infrared cameras that can see people in the dark.
"High-rise buildings, security fences or even the walls of a building are not barriers to increasingly common drone technology," Amie Stepanovich, director of the Electronic Privacy Information Council's surveillance project, told the Senate panel.
Civilian drone use is limited to government agencies and public universities that have received a few hundred permits from the FAA. A law passed by Congress last year requires the FAA to open U.S. skies to widespread drone flights by 2015, but the agency is behind schedule and it's doubtful it will meet that deadline. Lawmakers and industry officials have complained for years about the FAA's slow progress.
The FAA estimates that within five years of gaining broader access about 7,500 civilian drones will be in use.
Although the Supreme Court has not dealt directly with drones, it has OK'd aerial surveillance without warrants in drug cases in which officers in a plane or helicopter spotted marijuana plants growing on a suspect's property.
But in a case involving the use of ground-based equipment, the court said police generally need a warrant before using a thermal imaging device to detect hot spots in a home that might indicate that marijuana plants are being grown there.
In some states economic concerns have trumped public unease. In Oklahoma, an anti-drone bill was shelved at the request of Republican Gov. Mary Fallin, who was concerned it might hinder growth of the state's drone industry. The North Dakota state Senate killed a drone bill in part because it might impede the state's chances of being selected by the Federal Aviation Administration as one of six national drone test sites, which could generate local jobs.
A bill that would have limited the ability of state and local governments to use drones died in the Washington legislature. The measure was opposed by the Boeing Co., which employs more than 80,000 workers in the state and which has a subsidiary, Insitu, that's a leading military drone manufacturer.
Sen. Rand Paul, R-Ky., recently drew attention to the domestic use of drones when he staged a Senate filibuster, demanding to know whether the president has authority to use weaponized drones to kill Americans on American soil. The White House said no, if the person isn't engaged in combat. Industry officials worry that the episode could temporarily set back civilian drone use.
"The opposition has become very loud," said Gitlin of AeroVironment, "but we are confident that over time the benefits of these solutions are going to far outweigh the concerns, and they'll become part of normal life in the future."
Associated Press writer Michael Felberbaum in Richmond, Va., contributed to this report.
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