What image jumps to mind when you hear the word “drones”?

You might once have conjured images of vast, unfeeling robot armies, military surveillance or aerial strikes. But drones also are practical devices that are poised to become part of our lives. By the end of the decade, the FAA says, as many as 10,000 of them could be sharing U.S. airspace.

So, should we be afraid?

Maybe. Maybe not.

Drone by definition

A drone is any flying machine without a person in it; they’re also known by the term “unmanned aerial vehicles,” or UAVs.

That includes fairly large, sophisticated and expensive military drones, as well as tiny hovering copters flown by hobbyists or used in industries including real estate, marketing and even agriculture. A $60 remote-control Quadro helicopter from Radio Shack, which is made for kids 8 and older, is, by definition, a drone.

In the near future, it’s likely that drones will come in all shapes and sizes, some as tiny as insects, and instead of costing hundreds or thousands of dollars, might eventually become practically disposable in price.

Many people are coming to realize how a small aircraft that can hover in the air could be very useful — in a lot of ways.

Developers say drones could be used to pick up and drop off packages (Amazon’s stated intent), to avoid traffic, assist the visually impaired or find a lost dog.

Colin Guinn can rattle off a list of commercial uses for drones, none of which involve spying or doing harm to people.

“In agriculture, you can find hot spots in crops to see where they need more water or where they can use less pesticide,” said Guinn, the CEO of DJI Innovations in Austin, Texas, the North American arm of Hong Kong-based DJI. “You could do power line and transmission line inspection work, things that it’s ludicrous we would be letting humans do,” he said.

Insurance agents could do a hail damage flyover after a storm. Rescue workers could do a quick inspection of an area in a search-and-rescue or after a natural disaster.

Despite their promise, there are major concerns about how drones might be used in the United States and abroad. A federal law requiring the FAA to make rules for drones by 2015 is calling into question who’ll be able to use drones — and for what. Already, nine states have passed bans restricting some drone use.

Other obstacles

Privacy concerns and bad publicity about military drone strikes might not be the only obstacles to UAVs going mainstream.

In an article for Scientific American, Kyle Wesson, a doctoral candidate, and Todd Humphreys, an assistant professor, both at the University of Texas, suggest that drones could be dangerous.

GPS signals that drones rely upon could be cut off or hijacked. Someone could take control of an innocent person’s drone using those techniques to spy or to crash and cause damage. Drones also could be involved in accidental collisions with other drones or other kinds of aircraft.

While Wesson maintains he’s not arguing for a ban on drones, he does say that the patchwork of state laws coming onboard aren’t addressing privacy and security issues in a consistent way. In addition, many of the laws that have been passed might be trumped by federal mandates in 2015.

“People want to use them. They’re going to move forward,” Wesson said. “The question is what the regulatory landscape will look like.”