A Silicon Valley county has become the first in the United States to vote in a new law that requires "continued oversight and regular evaluation" for law enforcement agencies prior to the acquisition of surveillance technology.

The ordinance, which was unanimously approved by the Santa Clara County Board of Supervisors on Tuesday, requires that the county sheriff's and the district attorney’s offices seek board approval before those agencies even begin the process of obtaining new snooping gear. The agencies are not required to immediately notify the board in exigent circumstances, but they must do so within 90 days.

Agencies must also submit a usage policy to the county government and, notably, an "Annual Surveillance Report," which should describe what data the device captures, how the agency deals with information collected about people not suspected of any wrongdoing, and whether the gear has been effective, among other requirements.

"The ordinance doesn’t prohibit the acquisition of any surveillance technology," Supervisor Joe Simitian, a longstanding local privacy advocate and former state senator, told Ars. "It says if you’re going to acquire any surveillance technology, let’s talk about privacy and due process rights."

"The issue is not the technology. The question is whether or not we have the wisdom to use the technology appropriately," he added.

Catherine Crump, a law professor at the University of California, Berkeley, said that she was not aware of any county nationwide to implement such a law, but she noted that Seattle has a similar municipal law.

"It’s particularly important that a tech savvy jurisdiction in the heart of Silicon Valley model how we can achieve the benefits of surveillance technology without abandoning people’s privacy rights," she e-mailed Ars. "It seems likely that other counties and cities will use what Santa Clara has done as a model and feel more comfortable creating ground rules in this area."

Similarly, Elizabeth Joh, a law professor at the University of California, Davis, also said she didn't know of any similar county-level ordinances.

"If secrecy breeds suspicion, openness encourages oversight," she e-mailed Ars. "In the post-Snowden era, communities want to know *how* the police are doing what they do, not just that they are achieving data-driven results."

A delicate balance

In the 10-page ordinance, the Board acknowledged California’s right to privacy, which is enshrined in the state constitution, but also noted that:

…surveillance technology may also be a valuable tool to bolster community safety and aid in the investigation and prosecution of crimes. To balance the public's right to privacy with the need to promote and ensure community safety, the Board finds that any decision to use surveillance technology must be judiciously balanced with an assessment of the costs to the County and the protection of privacy, civil liberties, and civil rights.

The Santa Clara Board made headlines over a year ago when it refused to approve the purchase of cell-site simulators, better known as stingrays. Simitian led the charge in trying to pierce the veil of secrecy when the county sheriff tried to acquire stingrays using federal grant money—ultimately the board rejected the sheriff's efforts.

Civil liberties groups, including the American Civil Liberties Union of California, lauded Tuesday's vote.

"When law enforcement gets to conceal the use of surveillance tools, they also get to conceal the misuse and abuse of these technologies," Nicole Ozer, a director at the ACLU of California, said in a statement. "Law enforcement in Silicon Valley has attempted secret drone purchases, lobbied to buy invasive cell phone trackers, and used social networking software to target Black, Asian-American, and Muslim protesters, so there certainly was a need for greater transparency and oversight."