Coming soon to a window near you: flying spy-bots.

That's one fear, at least, as the technology behind unmanned aerial vehicles, or drones, grows ever better and cheaper. There are potential benefits too, from advertising real estate to assisting search and rescue teams.

As federal regulators work on new safety rules for the budding field, questions are being raised in Massachusetts and Congress about privacy, profit and a horde of domestic drones just over the horizon.

'It's Going To Be A Fun Technology'

High-tech entrepreneur Terry Holland's unmanned aerial vehicle looks nothing like the Predator drones the United States has used overseas to hunt and kill suspected terrorists. It's more like one of those radio-controlled helicopters a kid might find under the Christmas tree — albeit an overgrown and highly technical version.

On a recent sunny day, Holland prepped his "quadcopter" for flight outside his Pittsfield home. A series of electronic beeps sounded and LED lights flashed as the machine searched for satellite contact to get its GPS coordinates.

"Now I'm going to start it up,” Holland said.

Rising steadily from the driveway, the two-and-a-half pound drone looked pretty futuristic: sleek white X-shaped body, four arms with propellers whirling at the ends, and a high-definition camera dangling from its belly.

It was pretty noisy.

"It's sort of like an electric yard string trimmer, a little weed-whacker in the air," he said.

It quickly got up around 35, 40 feet in the air. From a LCD screen on his remote control box, Holland can see everything the drone's camera sees. He can control the camera's ultra-smooth movements and capture digital video for later editing. In all, his quadcopter and related equipment, which he bought online, set him back around $7,000.

"This is not so much what you would find with the hobby setups,” he said. “This is how you get the nice sort of Hollywood-style shots."

Holland has flown his rig alongside Olympic athletes in training to help analyze their form. He's guided it over and through a historic inn and equestrian center in rural Richmond, creating an elegant video of the property for a real estate firm. And the camera's polarized lens, he says, is good for spotting invasive aquatic plants near his family's lake camp.

"I love watching converging technologies and seeing new markets come into being that have never been possible before,” he said, once the drone had come to a smooth landing. “The things we haven't even thought of that this will be able to do for us — it's going to be a fun technology."

Holland's far from the only one who's excited.

The Next Big Thing In Law Enforcement

"That's a no-brainer. If the FAA says we can use them, then you can bet that we're going to put them up,” said Chris Baker, who commands the Metro Law Enforcement Council's SWAT team, which covers more than 40 Boston-area cities and towns. Baker said unmanned aerial vehicles are the next big thing in law enforcement: They can help with crowd control, search and rescue efforts and, Baker said, protecting front-line cops.

"Like a fugitive search, to be able to just put reconnaissance up above where we're searching,” Baker said. “It's just another layer of safety. The more information that we can get, the better and more concise and clear decisions we can make."

Soon after last year’s Boston Marathon bombing, then-Boston Police Commissioner Ed Davis speculated that drones could be deployed above this year’s marathon. Other law enforcement agencies, such as MetroLEC and state police, have begun to consider drones, and even budget for them. Baker said MetroLEC backed off plans last year to purchase and deploy the technology because federal regulations at the time seemed cumbersome and vague.

Nonetheless, law enforcement’s interest in drones is drawing attention from lawmakers and civil liberties groups. They are concerned about drones' potential use — or abuse — in government surveillance. In other states, there has been a public backlash when police departments have proposed using drones.

Privacy Questions And Concerns

"Drones are a perfect example of one of the places where the law has failed to keep pace with the technology," said Kade Crockford, who monitors technology issues for the Massachusetts chapter of the American Civil Liberties Union.

Crockford said drones can provide police with an unprecedented volume of personal information. To some degree it’s a simple matter of money: Drones cost a lot less than planes or helicopters to buy and deploy.

"Drones in fact can have all sorts of different technologies on them,” she noted. “They can have cellphone sniffers on them, to determine every single person who is in the building based on the information that their cellphone is sending. The infrared cameras are another thing they can have on them. ... And there are obvious Fourth Amendment questions."

That is, questions about the constitutional right to privacy. The ACLU is supporting a bill now in the state Legislature that would require police in Massachusetts to seek a warrant before using drones for surveillance. There would be exceptions for emergencies that pose a threat to life or safety.

On Capitol Hill, Massachusetts U.S. Sen. Edward Markey has filed similar legislation. And Markey goes further, seeking to protect against invasions of privacy by private-sector drones. He'd create a registry for what’s expected to be a boom in commercial drone enterprises — think of Google mapping projects or Amazon’s delivery systems. Markey would require reports on the kinds of data they planned to collect and how long they would keep it. Markey believes legislation needs to be enacted quickly, before drones start to fill the skies.

"We are entering a brave new world and just as we have rules of the road, we now need rules of the sky,” said U.S. Sen. Edward Markey (AP File)

“A company could fly a drone over anyone's backyard, collect whatever information they'd like, sell it to whoever they want, and the individual would never know,” he said. “So we are entering a brave new world and just as we have rules of the road, we now need rules of the sky."

Civil liberties defenders do see an upside.

At a recent Capitol Hill hearing on domestic unmanned aerial vehicles, the national ACLU’s legislative counsel, Chris Calabrese, told lawmakers, including Markey, that while the right to privacy was at risk, drones could also be used by citizen watchdogs — much as cellphone cameras are now — to monitor police activity and document civil rights abuses. Journalists too, Calabrese said, will find important new ways to report on events using unmanned aerial vehicles.

For now, the Federal Aviation Administration is barring most commercial uses of drones, pending issuance of new rules at the end of 2015. The FAA this month designated six testing grounds around the country, including 200,000 acres at Joint Base Cape Cod, to help create safety protocols for domestic drones.

The Cape project’s coordinator, H. Carter Hunt Jr., said that creating privacy rules and seeking input from neighbors will be one of the first orders of business. And he said developers of all types are raring to go: Military applications are already being tested, and there are proposals to test unmanned aerial systems to track whale pods, or crop development.

"We do have one very interesting one, and that's a group of MIT graduate students who have hooked up with Harvard Medical School to take a UAS and use it to deliver vaccines in underdeveloped countries,” Hunt said.

Still, some say that the U.S. is falling behind other countries, like Japan and Australia, in unleashing the technology's potential, and they are calling on the FAA and Congress to act more quickly. Pittsfield entrepreneur Holland said he’s ready to turn his passion into profits, even as he recognizes the legitimate safety and privacy issues involved.

“I wouldn't want one of these things flying through my backyard without my permission, so I just treat, sort of, people's privacy the same way I want mine treated,” he said. “It's incumbent upon us to be clever enough to have the appropriate rules and regulations in place to protect ourselves from ourselves.”

For the time being it looks like Holland and his fellow drone-users will just have to wait — and keep their batteries charged.