Last week, Santa Clara County—which encompasses much of Silicon Valley—set a new standard in local surveillance transparency after months of activism by residents and allies from across the Bay Area. Their efforts, and the policy it enabled, suggest an overlooked strategy in the national battle to curtail unaccountable secret mass surveillance.

While federal agencies play a controversial role in monitoring Americans, their local counterparts also conduct similar activities—not only in the context of counterterrorism, but also in the name of routine public safety. Concerns about the militarization of local police have long united Americans across the political spectrum, but the metastasis of surveillance platforms across local police departments, county sheriffs, and state highway patrols too often went largely unnoticed until recently.

Concerns about the militarization of local police have long united Americans across the political spectrum.

Cell-site simulators (commonly referred to by the trade name of the early versions of the devices, Stingray) are an example of police surveillance equipment that have grown particularly controversial. They essentially mimic cell phone towers in order to monitor data and voice traffic, and were so secret that prosecutors around the country resigned cases based on evidence collected from cell-site simulators rather than disclose their existence to courts.

But while Stingrays have prompted increasingly widespread concerns in the last few years, they have been deployed in U.S. cities for a decade. In Baltimore alone, they were used thousands of times without judicial oversight or legislative awareness—let alone approval—since 2007.

The new measure will impose several requirements on all Santa Clara County agencies. First, it will require them to seek affirmative approval from the county Board of Supervisors before purchasing new surveillance equipment. It will also require agencies to develop usage policies providing protections for civil rights and civil liberties for the Board to review and approve. Finally, it will require annual reports to the Board enabling meaningful oversight of how agencies deploy surveillance equipment that the Board allows them to purchase.

Supervisor Joe Simitian, who sponsored the new Santa Clara law, emphasized that it will subject not only existing surveillance technologies to legislative oversight, but also technologies that have yet to be developed. As explained by the ACLU of Northern California’s Nicole Ozer, "Silicon Valley's local lawmakers made sure the law passed today was future-proof by creating consistent rules for all the surveillance technology that currently exists and those we know will come."

My colleague Adam Schwartz, who lives in Santa Clara County, spoke in support of the ordinance before the county Board, noting that:

Each new government surveillance technology raises a thicket of difficult questions. Should it be adopted at all? What are the benefits and costs? Will it actually make us safer? What are the privacy safeguards? These questions should be answered by the Santa Clara County Board, before any county agency adopts a new surveillance technology. The general public should be heard, too. When all concerned stakeholders participate, we make better decisions.

Among the other voices promoting the bill were three local groups participating in the Electronic Frontier Alliance, including the Oakland Privacy Working Group, Restore the Fourth-Bay Area, and the Peninsula Peace and Justice Center. Members of each of these groups spoke before the county Board of Supervisors, organized support for the proposal in live events and over social media, and reached out to other organizations and their communities to seek their support for greater transparency.

Other cities around the Bay Area have previously taken steps to curtail surveillance by local police. For example, San Francisco adopted a measure in 2008 reiterating local privacy standards to curtail federally coordinated surveillance using city resources. In particular, it required S.F. Police Department officers participating in FBI-coordinated Joint Terrorism Task Forces to comply with more protective state & local standards, rather than opportunistically choosing federal law where more permissive.

Securing even greater protection for civil liberties beyond transparency, the City of Berkeley adopted a policy in 2012 imposing substantive and procedural limits on intelligence collection. That policy included five discrete components approved by the City Council that require reasonable suspicion of criminal activity as a predicate to justify the collection of intelligence information, categorically prohibit Suspicious Activity Reports (SARs) based on non-violent civil disobedience, allow city officials to review intelligence reports submitted to regional fusion centers, and require an annual audit of all SARs.

The measures adopted in Berkeley promote transparency while also aiming to prohibit the untethered, unfocused, and unconstitutional monitoring that has grown routine in many jurisdictions, where functional limits on collection, retention, or dissemination of intelligence information have remained elusive. Like Santa Clara County, the measure in Berkeley required sustained mobilization by a diverse local coalition that rendered opposition by local policymakers untenable.

In addition to challenging intelligence collection unhinged from suspicion of crime, the Coalition for a Safe Berkeley also mounted several other successful campaigns. One restrained police militarization by blocking the procurement of an armored vehicle, and another limited cooperation with federal officials using local public safety resources to facilitate immigration enforcement and build a vast biometric database including Americans.

As similar efforts proliferate across the country, we plan to invite local coalitions to collaborate on shared, decentralized campaigns to address continuing controversies at the federal level. For instance, grassroots efforts to seek greater transparency into police use of surveillance technology can build local networks poised to support the scheduled expiration next year of section 702 of the Foreign Intelligence Surveillance Act.

If you'd like to bring the battle to stop mass surveillance to your community, join the Electronic Frontier Alliance.