(CBS News) - Unmanned aerial vehicles, a key weapon in the hunt for terrorists overseas, are coming to America. In February, President Barack Obama signed a bill that opens U.S. airspace to thousands of these unmanned aircraft.

The drones come in just about any size you want - as large as a passenger plane - or as small as a hummingbird.

"There's no stopping this technology," said Peter Singer, a Senior Fellow at the Brookings Institution and perhaps the country's foremost authority on drones. "Anybody who thinks they can put this genie back in the box - that's silliness."

Singer watched them dramatically alter the American battlefield overseas, and says they're about to become the next big thing at home.

"They're technologies that not only give you capabilities that you couldn't have imagined a generation earlier," Singer said. "But they're also technologies that cause questions that you weren't asking yourself a generation earlier."

Sparsely populated Lakota, N.D., is the first known site where a drone was used domestically to help arrest a U.S. citizen. It was the case of Rodney Brossart, a rancher accused of refusing to return a herd of cows that wandered onto his land. When police tried to move in, the family allegedly greeted them with loaded weapons.

Sgt. Bill Macki, who runs the SWAT team in nearby Grand Forks, called in the reinforcements: a Department of Homeland Security Predator drone - a massive aircraft that until now most people associate with Hellfire missiles and strikes against terrorists.

"I can't really get into what the dispute was over," Macki said. "What I can tell you is the SWAT team wasn't there over a property dispute. The SWAT team was called out to render assistance reference to armed subjects. ... And using the unmanned aerial vehicle seemed appropriate in this instance."

Brossart's lawyer is looking at challenging the drone use. It's a potential test case for the country, because the rest of the country's getting a lot more of them. Everyone wants an eye in the sky: real estate agents to view properties; farmers to find thirsty crops; energy companies to build pipelines; local police departments want to launch neighborhood surveillance flights, or find hard to catch criminals.

Rep. John Mica, R-Fla., chairman of the House Transportation and Infrastructure Committee, thinks the FAA was dragging its feet on allowing domestic drones. "No question about it. And that's why we acted," Mica said. The committee just passed legislation that the FAA estimates will put 10,000 drones in the sky by 2017.

Singer expressed concerns over safety, saying that while legislation did put in place rules to prevent drones from colliding with passenger planes, it did little to clarify who can operate them and who it can watch.

"That drone is not just picking up information on what's happening at that specific scene, it's picking up everything else that's going on," Singer said. "Basically it's recording footage from a lot of different people that it didn't have their approval to record footage.

Should people be worried that Big Brother is coming to watch them? "Well, there's always that concern," Mica said. "But there are means of tracking folks through cell phones, their computer usage. We live in a new age."

Ninety percent of the military's small drones are made at AeroVironment. CBS News needed clearance from the Defense Department to enter the factory floor. The next big market for AeroVironment? Small drones for local police.

"The average person probably doesn't even realize that these small, back-packable systems are used as extensively as they have been," said AeroVironment vice president Steve Gitlin.

Gitlin gave CBS News a tour, and rare, in-field demonstration. One drone, the Raven is four feet wide. What it likes in size, it makes up for in camera quality.

"People are going to use it for both good and bad," Singer said. "It's going to raise incredible new opportunities but also new challenges."

Singer believes that for every local police department trying to keep people safe, a less well-intentioned operator may be tempted to use drones for no good. And right now, there's little preventing either side from doing whatever they want.

"Like it or not, unmanned systems are the future," Singer said. "Unfortunately we're not ready for them - everything from our policy to our laws to the deep, deep ethical questions."