You probably don’t expect the government to log and track your personally identifying information, despite having broken no laws, just because you attended an event at the fairgrounds. That would be preposterous in the Land of the Free.

But, according to the Wall Street Journal, federal agencies have joined forces with local police to deploy automated license plate reader (ALPR) technology at gun shows, with the aim of collecting attendees' plate information—without an explicit target. Gun show patrons are typically concerned about their Second Amendment rights, but what about the First Amendment?

ALPRs are high-speed camera systems that capture the license plates of every vehicle that passes into view. These images are then translated into machine-readable characters that can be run through police and driver databases. The scans are also often added to massive ALPR databases. In aggregate, this data can reveal patterns of behavior, such as when you leave for work, where you sleep at night, what doctors you visit, who you hang out with, and, yes, whether you attend gun shows.

ALPR is a form of mass surveillance since it captures information on every driver, not just those suspected of involvement in crimes. Most states and local jurisdictions have not enacted any kind of public accountability for these systems.

We must demand it.

EFF has joined a broad coalition to support the Community Control Over Police Surveillance (CCOPS) campaign, which seeks to ensure that all members of the community, and not just a few police executives, get to decide whether or not to allow the police to deploy new surveillance tools.

The Crossroads of the West Gun Show in Del Mar, California, is a popular event that draws crowds of 6,000-9,000. ICE agents colluded with local law enforcement officers in 2010 to use license plate readers mounted on officers’ cars to gather information on vehicles at this gun show, according to a federal Immigration and Customs Enforcement email (recently released after a Freedom of Information Act request). Police then cross-referenced that data with license plates headed south into Mexico in an attempt to find a smuggling connection.

Perhaps the biggest problem with this tactic is that the police had no specific target. Rather, this was a dragnet operation that collected information on thousands of innocent people, without evidence of any particular threat or criminal wrongdoing. According to officials, there were no arrests made or investigative leads generated as a result of this mass surveillance. What they did collect, however, was a list of individuals who apparently have an interest in firearms.

Due to the absence of independent oversight of ALPRs and other forms of street-level surveillance, we don’t know how long the police retained the data, who was able to access it, nor for what purpose. A new California state law (enacted with EFF support) requires agencies that use ALPRs to adopt and post a usage and privacy policy; however, it was not in effect at the time. In San Diego County, where Del Mar is located, law enforcement agencies now retain ALPR data for 12 months.

Bob Templeton, the CEO of Crossroads of the West, had no idea that police deployed license plate readers at this Del Mar event. Templeton told a reporter, “[i]t’s obviously intrusive and an activity that hasn’t proven to have any legitimate law-enforcement purpose.” He added that his customers, if they knew what had taken place, would be “resentful” of being targeted in that way.

ICE is not alone in its desire to deploy ALPRs at gun shows. Emails from 2009 obtained by the ACLU reveal that the Drug Enforcement Agency and the Bureau of Alcohol, Tobacco, Firearms, and Explosives considered working with local law enforcement agencies throughout Southern California and Arizona for the same purpose. Officials say that those plans were never executed.

The Wall Street Journal asked John Chigos, CEO of PlateSmart Technologies, Inc., one of the companies that distributes ALPRs, about the mass surveillance at Crossroads of the West. He said, “I think this was a situation that shows we need to establish policies for license plate readers, like any new technology.” He’s absolutely right.

We need to act—NOW. The alternative is a world where every aspect of our lives is digitized, warehoused, and analyzed at the whim of local law enforcement, just in case our highly personal information somehow turns out to be relevant to a police investigation. That’s unacceptable.

In order to protect civil liberties, police should be banned from deploying surveillance tools unless they get permission from elected officials subject to a transparent review process in which all members of the community have a voice. If elected officials decide to approve the new surveillance technology, the police must adopt, obtain approval of, and publish clearly defined use policies that remove ambiguity and subjective interpretation. A good example of a law that requires such transparency and democratic control is the local ordinance recently passed in Santa Clara County.

In pursuit of surveillance transparency, EFF and the ACLU of Southern California are currently engaged in a legal battle with law enforcement agencies in Los Angeles over access to license plate reader data. That case is currently before the California Supreme Court, which must decide whether agencies can claim a blanket law enforcement exemption to disclosure in order to deprive the public access of records that would inform the debate over ALPR technology.

If you’re wondering what you can do to protect yourself against mass surveillance at the hands of law enforcement, encourage your representatives to adopt the newly launched Community Control Over Police Surveillance initiative (CCOPS). It’s a nationwide, local-level reform effort that seeks to bring accountability to the process of acquiring and using new surveillance tools. You should also visit communityctrl.com to explore more ways in which you can make a difference.