California Police Scanned More Than 1 Billion License Plates — Rarely Finding Cars On 'Hot Lists'

A license plate reader mounted on the trunk of a Metropolotian Police Department car in Washington, DC. It automatically records details about the license plates of automobile that drive by. (PAUL J. RICHARDS/AFP/Getty Images)

California's law enforcement agencies scanned license plates more than 1.1 billion times in 2016 and 2017, compiling massive databases of people's movement across the state while rarely detecting the cars on police watchlists, according to analysis conducted by a non-profit group that advocates for privacy.

The details come from the Electronic Frontier Foundation, which requested documents on license plate readers from police departments across the country. In all, the group obtained records from more than 200 agencies nationwide and counted more than 2.5 billion scans.

Among them were dozens in California. The Los Angeles County Sheriff's Department, the nation's largest sheriff's department, scanned 234.4 million plates during 2016 and 2017. That was the highest figure of the 200 agencies tracked by the EFF.

Other Southern California agencies also ran millions and millions of scans including:

  • San Bernardino County Sheriff (162.7 million)
  • Downey Police Dept. (64 million)
  • Beverly Hills Police Department (54.9 million).

License plate readers can be mounted on squad cars or traffic lights, and capture images of license plates that pass by, typically recording the time and location. The plate numbers are checked against department "hot lists" that include cars seen at crime scenes or connected to outstanding warrants.

A billion scans would be enough to scan every registered vehicle in the state 32 times. The true number of scans is likely much higher, since the report does not include many large California agencies, including the LAPD.

Police agencies argue that the license plate readers help them work faster and more efficiently.

"If you're driving around in a patrol car, you have one set of eyes," Darren Wyatt of the Anaheim Police Department told KPCC in 2016. "The cameras are around the entire vehicle."

They say the devices are vital tools in solving stolen car and missing persons cases.

TABLE: Look up license plate scans at California agencies in 2016 and 2017

Data from law enforcement agencies via Electronic Frontier Foundation, for 20016-2017. Not all California agencies available.

The technology has raised alarms about government surveillance. The data police compile enable them to track Californians' movements at a granular level, so authorities can use your driving patterns to determine where you worship, or if you visited an immigration clinic, protest or gun store.

So are we living in an Orwellian nightmare?

"I would say that we're getting close," said Dave Maass, one of the authors of the report. "License plate readers are indiscriminate forms of mass surveillance. That means they collect information on everyone, regardless of whether you're suspected of being part of the crime."

The overwhelming number of scans — hundreds of millions — fail to turn up plates of interest to police. Many departments report that roughly one in five hundred scans produces a "hit" that matches a plate of interest.

The rate can go even lower. At the Beverly Hills PD, just 0.02 percent of scans matched a plate on the agency's "hot list".

The report also sheds light on the widespread sharing of the data within law enforcement. Many local departments share their data with police agencies thousands of miles away.

For example, if your license plate is scanned in Cathedral City, police there share it not just with nearby cities, but with police in Springfield, Illinois and Miami, Florida. In all, Cathedral City shares data with 732 outside agencies.

Many agencies also share their data with contractor Vigilant Solutions' National Vehicle Location Service, whose details are shielded from to the public.

That widespread dissemination concerns the EFF's Masss. "Every time you add a different agency to who you share with, that is another vector for abuse or unauthorized access or hacking."

EFF officials said it's possible incorrect data is included in the files released to them, noting that "the law enforcement agencies we surveyed sometimes appeared not to fully understand how their systems worked." The group said any inconsistencies will be corrected once identified. They also called on the vendor, Vigilant Solutions, to publish its data, which they argued would "not only save our time, but also the time of every law enforcement agency staff member who must process our public records request."

A previous EFF report showed that the Long Beach PD had allowed ICE and CBP officers to search its license plate database. Two months later, the Long Beach City Council voted to adopt a "sanctuary ordinance".

While the report pins down the scope of license plate reader use at dozens of agencies, less is known about precisely how police use the technology. Maass called that "an intentional obfuscation by law enforcement and the company Vigilant Solutions," pointing to the restrictive agreements the company asks police to sign.

The issues connected to license plate readers are likely here to stay. The next frontier in police surveillence technology is facial recognition software, already in use at agencies around the country.


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