California Gov. Jerry Brown vetoed legislation that would have required the police to obtain search warrants to surveil the public with unmanned drones.

Brown, a Democrat facing re-election in November, sided with law enforcement and said the legislation simply granted Californians privacy rights that went too far beyond existing guarantees. Sunday's veto comes as the small drones are becoming increasingly popular with business, hobbyists, and law enforcement.

"This bill prohibits law enforcement from using a drone without obtaining a search warrant, except in limited circumstances," the governor said in his veto message (PDF). "There are undoubtedly circumstances where a warrant is appropriate. The bill's exceptions, however, appear to be too narrow and could impose requirements beyond what is required by either the 4th Amendment or the privacy provisions in the California Constitution."

At least 10 other states require the police to get a court warrant to surveil with a drone. Those states include Florida, Idaho, Illinois, Indiana, Iowa, Montana, Oregon, Tennessee, Utah, and Wisconsin.

As Slate described it, "California's drone bill is not draconian. It includes exceptions for emergency situations, search-and-rescue efforts, traffic first responders, and inspection of wildfires. It allows other public agencies to use drones for other purposes—just not law enforcement."

The widespread acceptance of drones has even caught the attention of a member of the US Supreme Court. Justice Sonia Sotomayor said two weeks ago that she was concerned over a lack of unified privacy standards concerning drones.

"There are drones flying over the air randomly that are recording everything that’s happening on what we consider our private property. That type of technology has to stimulate us to think about what is it that we cherish in privacy and how far we want to protect it and from whom," Sotomayor told a gathering at Oklahoma City University. "Because people think that it should be protected just against government intrusion, but I don’t like the fact that someone I don't know…can pick up, if they’re a private citizen, one of these drones and fly it over my property."

The American Civil Liberties Union urged the governor to sign the bill, AB 1327, from Assemblyman Jeff Gorell of Southern California. "California leads the nation in technological innovation. It should also lead the nation in protecting the privacy of its citizens."

Gorell told the Los Angeles Times that the veto was "very disappointing."

"We're increasingly living in a surveillance society as the government uses new technology to track and watch the activities of Americans," he said. "It's disappointing that the governor decided to side with law enforcement in this case over the privacy interests of California."