After all, says Sarah Moore, a partner in employment law firm Fisher & Phillips, “If drones can crash into the White House lawn, a tennis arena during the U.S. Open, or any number of prison yards across the country”—not to mention swooping uncomfortably close to a Presidential motorcade in Hawaii—“you can bet that your workplace is not immune.”

Since about 400,000 Americans found a shiny new drone under the Christmas tree this year, according to industry estimates, the number of flying machines controlled by consumers has topped one million.

The Federal Aviation Administration is struggling to keep up, requiring drone owners to register their gadgets beginning on December 21 for inclusion in a federal database. So many people tried in the first couple of days that they crashed the FAA’s web site.

Employers, meanwhile, are grappling with the question of whether they need a policy that restricts drone use by employees, Moore says. Because so many of the flying machines come equipped with state-of-the-art digital cameras, she adds, it’s a particularly pressing issue for managers concerned about protecting trade secrets.

Suppose you’re one of them. “It’s critical to take control of the airspace within and above your buildings, including parking lots and green spaces,” Moore says. “You should start by crafting a policy that identifies ‘no drone zones’ both inside and outside.” Security staffers in charge of maintaining these no-fly areas need training in how to respond to unwelcome air traffic, including whether or when to report suspicious drones to the police or even the FAA.

Some companies already use drones instead of video cameras to monitor what goes on inside their workplaces. While no federal law requires employers to give workers advance notice that they’re being watched, a patchwork of state and local privacy laws—and some union contracts—demand it. So attorneys generally recommend a policy that informs employees of any surveillance, by drone or otherwise.

It’s also smart to explicitly prohibit employees from bringing airborne toys to work, period, to avoid what Moore calls “potential legal exposures.” For example, she says, someone could use a drone to “capture footage which could become ‘Exhibit A’ in later government investigations or legal proceedings against your company.”

In the same way that the proliferation of smartphones prompted lots of employers to write up BYOD (bring your own device) policies, Moore says, “the next big thing is rules about BYOS, for ‘bring your own surveillance.’ Employees should leave their drones at home.”

As for how early in the New Year to start thinking about writing up a drone policy, she advises corporate clients to do it “before this issue lands on your desk—figuratively or literally.”