Daniel Terdiman/CNET

California police do not need to get a warrant to use surveillance drones. Democratic Governor Jerry Brown vetoed a bill on Sunday that would have required police to obtain a court-issued warrant when flying unmanned aerial vehicles in most situations.

"I am returning Assembly Bill 1327 without my signature," Brown wrote in a letter (PDF) to the California State Assembly. "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."

AB 1327 was introduced by Republican Assemblyman Jeff Gorell and easily passed both houses of the state's legislature last month.

While the bill addressed many non-law enforcement uses of drones by government agencies, the heart of the proposed law was geared toward ensuring police obtained warrants before deploying most surveillance drones. The only exceptions when a warrant wasn't required were "emergency situations," such as fires, hostage crises, chases, search and rescue and environmental disasters.

The bill had wide support among privacy advocates who said police surveillance drones tread on individual's privacy. These advocates say that drones equipped with sophisticated camera equipment can hover quietly and for long periods of time at altitudes well below helicopters -- which police have long used for warrantless surveillance.

"I am very disappointed by this democratic Governor's decision to veto a bill that provided commonsense protections to protect privacy rights and civil liberties," Gorell said in a statement. "We live in an era of government surveillance, where powerful government agencies like the NSA and IRS have demonstrated blatant disregard for Americans' privacy rights. In Congress, I will make personal privacy a top priority and work on establishing common sense drone restrictions that California failed to establish."

To date, there are six states that have already enacted laws requiring police to obtain warrants for drone surveillance.