As the FAA struggles with the challenges of regulating drones, the devices have already spurred a legal scuffle between hunters and animal rights activists. In October, PETA launched the Air Angels program, a line of drones meant to let concerned citizens report illegal activity by hunters. Hunting groups pushed back and, as of January 1st, the program has been made illegal in Illinois with a law prohibiting "the use of drones to interfere with hunters or fishermen." The only problem: PETA isn't buying it.

"It's being done on public land in a nonresidential area."

According to Jared Goodman, PETA's director of animal law, Air Angels aren't about interference at all. "The intention is simply to monitor what hunters are actually doing," Goodman says, "and whether they're engaged in any illegal activity, such as drinking in possession of a firearm or illegally using spotlights or feedlures." If they spot any illegal activity, PETA members are advised to report it to a local game warden and not take any further action themselves. As a result, PETA is eager to challenge the new law, but even more eager to test out the project in states.

Hunting groups like The US Sportsman's Alliance, which has applauded the Illinois law, aren't so sure. "PETA's approach here was essentially just to get some press," says CEO Nick Pinizzotto. He says his members were incensed by the idea of the project, but he hasn't heard any instances of hunters actually being harassed by the drones. (Goodman, in his defense, says "dozens" of the Air Angels have been sold through PETA's website.)

"I don't think Americans in general appreciate being spied on."

Still, the legal issues are thorny enough to cause problems even without widespread hunter-watching programs. If the Illinois law is challenged, it's not clear hunters would be able to appeal on privacy grounds. "It's being done on public land in a nonresidential area," Goodman says. "There's no reasonable expectation of privacy there. Any other hunter who's on the same land could see the same thing." It might be more unnerving to be watched by a drone than a person, but the legal distinction is less clear, which presents regulators with real uncertainties as they look to draw up rules for the bots.

Even if the law isn't settled, Pinizzotto is sure public opinion is on the side of hunters. "I don't think Americans in general appreciate being spied on, whether it's hunting or anything else," he says. "People are really concerned about the idea of drones. If they can spy on me hunting, what else can they do?"