Across the country, private companies are deploying vehicles mounted with automated license plate readers (ALPRs) to drive up and down streets to document the travel patterns of everyday drivers. These systems take photos of every license plate they see, tag them with time and location, and upload them to a central database. These companies—who are essentially data brokers that scrape information from our vehicles—sell this information to lenders, insurance companies, and debt collectors. They also sell this information to law enforcement, including U.S. Department of Homeland security, which recently released its updated policy for leveraging commercial ALPR data for immigration enforcement. 

The Atlantic has called this collection of our license plates “an unprecedented threat to privacy.” This data, collected in aggregate, can reveal intimate details about our lives, including what doctors we visit, where we worship, where we take our kids to school, and where we sleep at night. Companies marketing this data claim that the technology can predict our movements and link us to our associates based on which vehicles are often parked next to each other. 

Take Action 

Tell your state senator to vote yes on S.B. 712

To address this threat, EFF is a sponsor of S.B. 712, a California bill introduced by Sen. Joel Anderson that would allow drivers to cover their license plates when lawfully parked. The legislation, which was filed in 2017, will receive a fresh vote by the California Senate Transportation and Housing Committee on Jan. 9. (UPDATE: The committee passed the bill 8-2.)

How does this make sense?

Current California law forbids vehicle owners from doing anything to their license plates that would interfere with ALPRs.  However, there is one exception: drivers may cover their entire vehicles to protect their cars from the elements. S.B. 712 argues that if it’s OK to cover the entire vehicle, including the license plate, then it should be legal to cover just the license plate, presuming the driver is parked legally.  Law enforcement officers would have the authority to lift the cover to examine the plate number. 

In practical application, S.B. 712 would allow a patient to cover their plate when they park at a reproductive health clinic to keep that sensitive medical information private. It would allow a visitor at a mosque, church, or temple to cover their plate to protect their religious activities from being sold by data brokers. Clients of immigration lawyers could cover their plates when they visit the firms to ensure they can access counsel without triggering an Immigrations & Customs Enforcement alert. 

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Dave Maass testifies on S.B. 712 in 2017

In opposing the bill, law enforcement has overstated the usefulness of ALPR data collected from parked vehicles. During a May 9, 2017 hearing, law enforcement representatives were unable to present any data supporting their claims. Following that hearing, EFF filed dozens of public records requests around the state of California to find that data. We found that less than 0.1% of license plate data collected by police are connected to a crime at the point of collection, but the remaining 99.9% of the data is stored and shared anyway.

For example, the Sacramento Police Department collects on average 25-million plate scans each year. Only a tiny number of those plates, 0.1%, were connected to an active investigation when the information was collected. And yet the rest of the plates, 24.97 million of them, are shared with more than 750 agencies nationwide with little vetting or control.

The records further showed that some jurisdictions had even worse results: In 2016, the San Diego Police Department collected 493,000 plates, but only .02% (98 plates) were connected to a crime. Of those, only a single vehicle was connected to a felony. Over one 90-day period, the City of Irvine collected 217,000 plates, but again, only .02%-a grand total of 40 plates-were connected to a crime, usually vehicle theft. ­­­ 

EFF is joined by the ACLU in supporting this legislation. We believe S.B. 712 provides a balanced solution since it does not create a new burden on companies or state agencies, but rather empowers drivers to protect their privacy if they so choose.

Read EFF's letter in support of S.B. 712. For more information on ALPRs, you can review EFF’s Street-Level Surveillance project, which outlines how ALPRs work and the threat they present to privacy. 

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