The unarmed aircraft have been used to search for lost hikers, guide firefighters battling wildfires and check for damage after floods, the Los Angeles Times reported Friday. A drone was used this month in Alabama when a man shot a school bus driver and took a 5-year-old boy hostage.
The Federal Aviation Administration said that 327 of the 1,428 permits issued since 2007 are active. U.S. Customs and Border Protection is the largest user in the federal government with 10 Predator-sized aircraft patrolling the borders with Mexico and Canada.
Drones can save substantial amounts of money. Ben Miller of the Mesa County Sheriff's Department in Colorado said that a drone can stay in the air for about $25 an hour, compared to $600 for a manned helicopter.
Other law enforcement agencies are holding off. Michael Downing, who heads counter-terrorism operations for the Los Angeles Police Department, told the Times the department is waiting for FAA regulations on using drones in areas where the airspace is already crowded.
There are also privacy concerns about the domestic use of drones. A number of cities and states have already passed laws limiting their use for surveillance.
"Americans have the right to know if and how the government is using drones to spy on them," said Catherine Crump, an American Civil Liberties Union lawyer.