Have a drone? You’re going to have to register it with the U.S. Department of Transportation, according to NBC News.

The federal government will announce a plan within days that will require anyone who buys a drone to register it with the Department of Transportation, NBC reported Friday evening.

A Department of Transportation spokesperson told MarketWatch that U.S. Transportation Secretary Anthony Foxx and Administrator Michael Huerta of the Federal Aviation Administration will release more details on Monday at 12:30 p.m. Eastern time.

“The hobbyist drone community has self-regulated itself for decades,” said Lisa Ellman, co-chair of the unmanned aircraft systems practice at Hogan Lovells, a New York–based law firm. “But with the technology getting so cheap and improving so much, we have more and more drones.”

FAA official Rich Swayze said last month that the agency expects that a million drones could be sold this holiday season.

“A lot of people are buying them and thinking they are toys,” Ellman said. “They are not toys.”

Florida lawyer Jonathan Rupprecht, author of a book on drone law, said he believes any plan centered around drone registration is a necessary first step toward regulating drones but is curious how the regulation will play out and whether the rule will apply to hobbyists with small drones.

“It could get people off our backs,” Rupprecht said, referencing fears about drones’ use in spying operations and about crashes. “At some point the industry is going to have to realize we’re going to have to be regulated and we’re going to have to give up concessions right now.”

But he’s also doubtful that registering drones will be a valuable solution.

“Who is going to regulate this? Point-of-sale? Wal-Mart? Best Buy?” he asked. “What if I’m ordering parts off the Internet and put them together? That’s what the gun industry does.”

A registration number, he said, could quickly be lost if a drone is bought and sold multiple times.

And then there’s the question of what defines a drone — and what types of drones would be regulated. Drones weighing less than 1 pound can be purchased for less than $100 from companies such as the French drone maker Parrot PARRO, -1.08% . Drones are also widely sold online, including on Amazon.com AMZN, +5.69% and via the Apple Store.

Currently, operators using a drone for commercial purposes must have FAA authorization to fly commercially through what’s called a Section 333 exemption. All drone operators with a Section 333 exemption are already required to register the aircraft with the FAA.

The FAA estimates that there will be roughly 7,500 commercial drones in the skies within the next five years, but some in the drone community suspect that figure is low. The world’s largest drone maker, China-based manufacturer DJI, sold about 400,000 units in 2014 alone, according to Forbes.

Registration would likely help in investigations and in finding owners of lost or renegade drones, such as the one that crashed near the White House earlier this year, Rupprecht said. The owner of that drone, an off-duty government employee, turned himself in.

“The law says drone operators can’t recklessly endanger the public, but if you don’t know who (the drone operator) is, you can’t really enforce the law,” Ellman said. “People are buying these as toys and not realizing they need to be truly responsible.”