Automatic license-plate readers (ALPRs) have been in use since at least 1997, when they were deployed in London as part of a surveillance and security cordon targeting IRA terrorists. In the United States, state transportation departments use the license-plate readers on toll roads and law enforcement agencies harness the technology to find stolen cars and track criminals. But the readers can also track the activities of law-abiding Americans.
Six years ago, Mike Katz-Lacabe had a brush with the police department in San Leandro, California. The police had recorded his movements all over town. But they were not deliberately tracking him. The department had captured information about the San Leandro resident’s local trips as a police car fitted with an automatic license plate reader drove around the city. “Putting the data together and over a long period time, you can develop a history of a person and their daily routine,” says Katz-Lacabe, an independent California privacy activist who obtained his own license-plate records through a public records request. “You have lots of information that can help you determine the patterns of a person’s life: where they live, who they associate with, whether they go to a health clinic, Planned Parenthood, or a local marijuana dispensary.”
As law enforcement agencies increase their use of automatic license-plate readers, municipalities around the country have compiled databases that detail the residents’ movements. But, in many cases there are few or no regulations governing how police departments collect, store, and access this data. In 2007, 15 states had only one law enforcement agency using them and another 18 states did not have any agencies using the readers. Four years later, a 2012 International Association of Chiefs of Police report noted that nearly three quarters of the 70 law enforcement agencies surveyed by the Police Executive Research Forum used ALPRs; 85 percent of those agencies planned to obtain readers or increase using by 2016. The U.S. Drug Enforcement Administration, Customs and Border Protection, and other federal law enforcement agencies use ALPR records. These agencies draw on the license-plate records collected by state and local agencies, who share data with the feds in national “fusion centers.”
But most American police departments lack policies regarding who can access the data, when, and for what purpose. According to a 2012 IACP survey of 305 local, state, and tribal law enforcement agencies, just under half of them have policies in place. In 2012, Maryland alone gathered 85 million license-plate records. Nearly all of this information pertains to law-abiding Americans: Only 0.2 percent of the license plate reads in Maryland were associated with any wrongdoing, and 97 percent of those cases involved minor offenses like vehicle registration issues. Usually, this data is stored indefinitely, creating richer records of vehicles’ whereabouts.
Affixed to a police car, a license-plate reader can photograph as many as 3,600 plates per minute, instantly translating the images into searchable text. Any vehicle fitted with the technology can drive through a parking garage and capture the date, time, and location of virtually every car inside. The technology matches those photographs against a “hot list”: a database that includes vehicles that have been stolen or owned by criminal suspects, or people who have unpaid parking tickets. A police officer receives an alert when there is a match with a particular vehicle. Internal police documents show that police officers can pull up the records of a car in a specific date range and even plot the license-plate readings out on a map. ALPR systems can also tell users how often a particular car goes to a specific address and whether the vehicle is more likely to be seen during the day or night. Without the license-plate readers, individual police officers have to decide if a vehicle is suspicious, then call a dispatcher, relay the license-plate number, and wait to see if there is a match.
“We’re not talking about one officer reading your license plate, or about just a coincidental observation of an individual’s activities by another member of the public,” says Linda Merola, a criminology professor at George Mason University’s Center for Evidence-Based Crime Policy. “Once that data is out there and it’s in a large database, it can be connected with registered owners of vehicles and connected to specific individuals through motor vehicle department records.” When people know their movements are being tracked, she argues, they may stop engaging in certain activities like protests. According to Merola, no research has been done on the usefulness of storing ALPR records over the long-term. But there have been cases where law enforcement agencies used old license plate records to apprehend robbers, drug traffickers, and others.
The American Automotive Association (AAA) supports law enforcement agencies’ ALPR uses. But the organization views storing data on people’s movements as an invasion of privacy. “Establishing a time limit for the retention of data would allow police investigations to continue while simultaneously protecting the privacy of other motorists,” an AAA spokeswoman says. AAA supports “the shortest, most reasonable retention period possible,” around 60 days, she adds. David Roberts, an IACP policing technology expert at the police chiefs association, echoes these concerns. “The technology doesn’t carry privacy risks in and of itself,” he says. “The issues really surround how they’re managed, how long they’re retained, who can have access, and under what circumstances.”
Federal law enforcement agencies have a long history of targeting law-abiding groups from civil rights organizations in the 1960s to Cleveland-based activists and organizers before the 2016 Republican National Convention. Local police departments have also abused the technology. In 2004, Edmonton, Alberta, police used license plate readers to try to catch a local reporter driving drunk after he wrote a story critical of the department. Through 2006 and 2007, as part of their surveillance of Muslims, the New York Police Department used ALPRs to collect information on people who visited mosques.
License-plate proponents argue that the technology’s tracking abilities pale in comparison to surveillance tools like GPS devices. However, law enforcement officials must obtain a warrant to use GPS to track vehicles; most states do not require police to obtain a warrant to use license-plate readers. The technology’s defenders also say that privacy advocates exaggerate what the technology can and cannot do and stress that existing laws already cover how ALPR data is accessed and stored. Most importantly, they argue that the chances for abuses are minimal and that the law enforcement benefits outweigh the privacy risks, since so many intrusive types of technology are widely used. “A license plate identifies a car, not a driver,” says Steve DelBianco, head of NetChoice, an e-commerce trade organization. “If you read a plate of a car driving by, you don’t have a prayer of determining who owns the car or who’s driving it.” He adds, “When the LPR data is kept in private hands, it’s only revealed when the government is pursuing an official investigation.”
The use of license-plate readers by law enforcement has been shrouded in secrecy. A 2010 survey conducted in Fairfax County, Virginia, by George Mason University’s Center for Evidence-Based Crime Policy found nearly 90 percent of people didn’t know if their local police departments were using ALPRs or not. When the ACLU requested records from 587 police departments and state agencies about their use of license-plate readers in 2012, only 293 responded. And sometimes, when a police department partners with ALPR companies, they sign contracts pledging them not to publicly divulge any details about how it uses the technology. However, after the ACLU released its landmark 2012 report on the technology, public awareness about the readers has improved. “I ask people, ‘Have you heard of ALPRs?’ and steadily the number of people raising their hands has been going up,” says Crockford.
Most privacy experts have given up on the federal government taking the lead in regulating the technology: Gridlock in Congress means legislation is still far off. The Supreme Court, notoriously slow on matters of technology, is also a dead end. It took the high court nearly 20 years after mobile phones began to be widely used to rule that police needed a warrant to search them.
States have been slow to regulate license-plate readers, too. Between 2013 and 2016, 33 states introduced bills to regulate the technology but only 15 laws in 12 states were actually passed—and at least two of the laws expanded the use of license-plate readers. Some states have begun to set limits on how long government agencies can store the data, however. Several states have effectively banned the technology except in certain, limited circumstances. In 2007, New Hampshire became the first state to ban the use of the readers. Since then, Maine, Arkansas, and Utah have passed laws that only allow ALPRs for narrowly defined law enforcement purposes. Meanwhile, data retention limits have been imposed in Colorado (three years) and Tennessee and North Carolina (both 90 days). A California law passed in last fall limits storage of ALPR records to 60 days and requires law enforcement agencies to collect public comments before putting new regulations in place. In June, Vermont began requiring warrants for plate records older than six months.
Other states have had near misses on regulation. A bill proposed by Massachusetts Democratic State Senator Cynthia Creem, would have put a 48-hour limit on retention of license-plate records by law enforcement, require a warrant to access the data, and would prohibit government agencies from partnering with any companies that keep data any longer. The bill is “not an easy sell” in the Bay State at a time when a string of domestic and overseas terror attacks have heightened people’s fears, says Creem. The proposal did not advance in the recently concluded legislative session.
Nevertheless, there are some avenues for reform. The National Highway Traffic Safety Administration offers grants for states to buy ALPRs for “highway safety” and Catherine Crump, associate director of Berkeley Law’s Samuelson Law, Technology, and Public Policy Clinic, says the federal government could require states to adopt official ALPR policies as a condition of receiving those funds. The agency requires grant recipients to audit their usage of the readers to ensure that the technology is not abused; enforcement mechanisms include “administrative remedies” that could bar grantees from receiving future funding. When this reporter asked if the NHTSA would consider requiring departments to design ALPR-specific policies as a condition of grant funding, an agency spokesman said that decision would be up to Congress.
Police are not as enthusiastic about regulation, however. Last year, the International Association of Police Chiefs sent a letter to Congress warning against federal ALPR legislation before any measures had even been proposed. The ALPR industry also strongly opposes new regulatory efforts. Vigilant Solutions, a company that makes ALPR software, sued Arkansas and Utah claiming that the states had violated the company’s First Amendment rights; in Massachusetts, the company’s vice president testified against three bills limiting ALPR use. Vigilant and Trans Union, another company involved in the ALPR business, together spent more than $250,000 lobbying against the California privacy bill and ALPR bills in Massachusetts. Vigilant views these attempts to regulate law enforcement use of license-plate readers as products of ignorance and hysteria. “The need to have a search warrant will minimize the use of license plate readers and cause lives to be lost because crimes will not be solved,” says Brian Shockley, Vigilant’s vice president of marketing.
Despite opposition from police and ALPR manufacturers, there is bipartisan support for placing some new limits on the technology. The Utah and Arkansas bills passed with large Republican majorities. Arkansas’s bill was co-sponsored by then-Republican State Representative Nate Bell (who is now an Independent), who has received a 100 percent rating from the American Conservative Union. State Representative Nate Steel, the Democratic co-sponsor, says conservative support was crucial to the bill’s passage. “The coalition that built behind this bill seemed to be libertarian, conservative Republicans and a lot of ACLU progressive Democrats,” he says. ACLU policy counsel Chad Marlow is not surprised to see these types of coalitions. “By and large, issues involving privacy in general have very strong left-right support around the country,” he says.
More importantly, Arkansas law enforcement officials provided considerable input. Steel met with several police trade associations and organizations, including the Arkansas Prosecuting Attorneys Association and the Arkansas Association of Chiefs of Police, to hear their concerns and strike the right balance between privacy protections and law enforcement needs. Ultimately, Steel agreed to a compromise that allowed police to hold onto data that was part of an ongoing investigation. “I ended up having the support from police agencies because of that,” he says. Even industry representatives step away from their more uncompromising public attitude when it comes to specifics on retaining records. “I would have no objection to a one-year retention period by government,” says DelBianco of NetChoice, although he warns against arbitrary time limits.
Automatic license-plate readers can be valuable law enforcement tools. However, police departments and other agencies must address the concerns about possible abuses by overzealous or corrupt individuals that continue to hang over technology. Over the past several decades, civil libertarians and law enforcement officials have successfully developed regulations for other technologies that pose privacy concerns, from GPS tracking to wiretaps. License-plate readers will have to undergo similar scrutiny. “Civil libertarians, we’re not ridiculous people,” says Crockford of the ACLU of Massachusetts. “We want police to be able to solve murders, find people who are kidnapped, but there need to be strict limits.”