What if a delivery drone falls on your head? Thorny legal questions loom

Imagine you’re standing in your front yard when a drone flies overhead, delivering a package to one of your neighbors.

The drone goes over your house, flying much lower than a helicopter could. Would that be considered trespassing? After all, you didn’t even order the package. What if the drone took pictures of you and everything else in your yard as it went by; is that allowed? What if it malfunctioned and fell on your head — who would be at fault?

These are some of the thorny legal questions that will have to be answered as companies such as Google parent Alphabet, Amazon and UPS start preparing for a future where delivery by drone is more widespread.

This month, Alphabet subsidiary Wing became the first company to operate a commercial drone delivery service in the United States: It ferried tissues, bottled water, cough drops and other products to people in Christiansburg, Va. The town has only about 21,000 residents, and Wing’s delivery service is only for the last mile of a package’s journey, but there are plans for more coverage in the future.

UPS got permission from the Federal Aviation Administration recently to operate delivery drones at university, hospital and corporate campuses. Amazon, meanwhile, has long been working on its robotic delivery service.

But there are still questions about how drone systems will navigate privacy and trespassing issues and concerns about noise.

“Legal precedent is very thin here,” said Arthur Holland Michel, co-director of the Center for the Study of the Drone at Bard College. “Little of the existing law is based specifically on drones.”

It’s also unclear who will be the ultimate arbiter for these concerns. The FAA is in charge of aircraft safety, but questions of privacy or trespassing could be left up to...