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Nov 15, 2023

California legislation targets police use of license plate readers

Privacy advocates have sounded the alarm over the technology which is also used

Privacy advocates have sounded the alarm over the technology which is also used by federal government agencies

New legislation proposed in California aims to put limitations on law enforcement's use of automated license plate readers (ALPRs), a technology used to collect large amounts of data and track the real-time movement of hundreds of millions of people without a warrant.

California state senator Scott Wiener on Tuesday will introduce the License Plate Privacy act, which would require regular audits of police department's use of such technology, ban the retention of data that is not relevant to police's needs and restrict the sharing of any retained data.

The bill's introduction comes after alarm has grown among privacy advocates over the technology, which is used by hundreds of local police forces across the country, as well as by federal government agencies such as the Drug Enforcement Agency (DEA) and Immigrations and Customs Enforcement (Ice).

ALPRs use cameras mounted on police vehicles or a stationary location such as a highway overpass to collect images of license plates, documenting the image accompanied by the date, time and location of that vehicle and in some cases photographs of drivers and their passengers.

California legislation was passed in 2015 to limit the use of ALPRs but, without regular auditing, it is unclear how well police forces are following the requirements, proponents of the new legislation argue. A 2019 audit of police forces showed they were, in many cases, collecting excessive amounts of information and sharing them with hundreds of other agencies, often without clear reasoning.

Wiener told the Guardian he first began to consider legislation after the 2019 audit showed there were "basically no constraints" over how ALPR data was collected and used.

"We were seeing that ALPR use in California was quickly becoming the wild west," he said. "It is violating people's privacy, and we do not need a surveillance state in this country."

Data collected through ALPR can be widely shared among police agencies. On average, a given US police force shares such data with 160 other agencies. Some forces share the information with far more organizations. The Sacramento police department, the audit found, sends its data to well over one thousand agencies.

Dave Maass, a privacy advocate and researcher at the Electronic Frontier Foundation, said law enforcement agencies also at times lack knowledge about recipients of the data and how it is used.

An audit found that police forces of Fresno, Marin, and Sacramento all sent their information to the Missouri Police Chiefs Association. While this sounds like a public agency, it was in fact a private professional organization that advocates for pro-law enforcement legislation.

None of the jurisdictions that sent information to the association could demonstrate that they had evaluated this organization or that this group had a need to see the APLR data.

With a high rate of domestic violence among police forces, there is also a risk officers could access the data internally for unscrupulous reasons, tracking the movement and patterns of others, advocates have warned.

"That wide amount of sharing has been a real problem," Maas said. "There's this real question of why do they need to collect so much data? Why do they need to collect it, and why do they need to hold on to it for so long?"

There is also limited evidence such data is useful to police, Wiener said. As the 2019 audit showed, only 400,000 of the 320m images collected by the Los Angeles police department in recent years could be traced to vehicles that are of interest due to connections to crime.

The bill will be introduced Tuesday and will be voted on by committee in the next month. Wiener hopes such legislation will ripple into other states where the technology is used.

"One of the beautiful things about California is we are often able to get out ahead on addressing important issues – this is happening all over the place and my hope is we can become a model for such important laws," he said.