By Laura Zuckerman

SALMON, Idaho, April 11 (Reuters) - Idaho's Republican governor signed a law on Thursday that restricts use of drone aircraft by police and other public agencies as the use of pilotless aircraft inside U.S. borders is increasing. The measure aims to protect privacy rights.

In approving the law, which requires law enforcement to obtain warrants to collect evidence using drones in most cases, Idaho becomes the second U.S. state after Virginia to restrict uses of pilotless aircraft over privacy concerns.

"We're trying to prevent high-tech window-peeping," Idaho Senate Assistant Majority Leader Chuck Winder, sponsor of the measure in the Republican-led Idaho legislature, told Reuters earlier this year as the bill was pending in the legislature.

Current federal regulations sharply limit the number and types of drones that can fly in American airspace to just a few dozen law enforcement agencies, including one in Idaho, public agencies including the Department of Homeland Security and universities for scientific research.

But unmanned aircraft are expected to be widely permitted in coming years, raising fears about misuse of miniature devices that can carry cameras which capture video and still images by day and by night.

Lawmakers in Idaho and more than a dozen states this year introduced legislation to safeguard privacy in the face of an emerging market the unmanned aerial vehicle industry forecasts will drive $89 billion in worldwide expenditures over the next decade.

The measure Idaho Governor C.L. "Butch" Otter signed into law on Thursday requires police to obtain warrants to use drones to collect evidence about suspected criminal activity unless it involves illegal drugs or unless the unmanned aircraft is being used for public emergencies or search-and-rescue missions.

The Idaho bill, approved last week by the state Senate and the state House of Representatives, also bans authorities, or anyone else, from using drones to conduct surveillance on people or their property, including agricultural operations, without written consent.

Idaho's Republican governor couldn't be immediately reached for comment.

Americans are most familiar with drones because of the use of armed, unmanned aircraft by the United States for counter terrorism operations against Islamist militants in countries like Pakistan and Yemen.

The majority of unarmed drones expected to operate in U.S. airspace when restrictions are rolled back by the Federal Aviation Administration in 2015 weigh less than 55 pounds and fly below 400 feet, according to a September report by the U.S. Government Accountability Office.

Cash-strapped law enforcement agencies see small drones, which cost as little as $30,000, as money-saving, low-manpower tools that could locate illegal marijuana farms, seek missing children and track dangerous fugitives.

Yet worries about widespread snooping persist. In February, privacy concerns prompted the Virginia legislature to put a hold on drone use for two years, and grounded a plan by Seattle police to deploy two camera-equipped drones.

Civil uses for drones would likely emerge first after 2015, while a commercial market would develop more slowly as airspace issues are resolved, the GAO report shows. Possible uses include pipeline inspection, crop dusting and traffic monitoring.

The FAA's goal is to eventually allow, to the greatest extent possible, routine drone operations in U.S. airspace. (Editing by Cynthia Johnston and Todd Eastham)
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