What Are ALPRs?

There’s no independent research proving that ALPRs reduce crime. Headlines and supporting studies claiming otherwise are often produced by the companies selling ALPRs and the police agencies buying them.

For example, Flock Safety claims that 10% of reported crime in the U.S. is solved using Flock technology. But the study Flock cites was conducted by two Flock employees and “given legitimacy with the ‘oversight’ of two academic researchers whose names are also on the paper,” according to a report by 404 Media.

What research does exist is inconclusive at best:

“When small numbers of LPR patrols are used in crime hot spots in the way we have tested them here, they do not seem to generate either a general or offense-specific deterrent effect.” — Journal of Experimental Criminology

“There is not even a moderate degree of correlation between ALPRs and stolen vehicle recoveries, let alone any apparent causality.” — Automated License Plate Readers: A Study in Failure

Companies that make ALPRs have a history of poor security practices, which can lead to data breaches and unauthorized access to sensitive information. For example:

• In November 2025, a security researcher found Flock logins for sale on Russian hacking forums, since Flock negligently doesn’t require multi-factor authentication.
• In January 2025, Motorola Solutions’ ALPR system was found to have a critical security flaw that let anyone access live data — license plate numbers, make, model, color, timestamps, and even a live camera feed.
• In July 2025, Flock Safety exposed a misconfigured demo site that revealed its internal search interface, some source code, and a live admin API key with access to over 50 private data layers.

A study of ALPRs in Piedmont, CA found that less than 0.3% of ALPR hits might translate into a useful investigative lead. Most plates recorded were not on any hot list — yet police still logged information on people’s movements throughout the day.

Flock’s own transparency portals show that the vast majority of plates scanned are not on a hot list (vehicles suspected of crimes). For example:

• Oak Park, IL Transparency Portal
• Vallejo, CA Transparency Portal

There are many documented cases where people with access have knowingly used ALPRs to commit crimes and put people in danger. It’s often only after harm is done that an officer is caught and punished, if at all.

• Texas police used Flock ALPRs to track a woman who had an abortion across state lines
• A police lieutenant used Flock ALPRs to stalk his estranged wife in Kechi, KS
• A police officer accepted a bribe to run a woman’s license plate in Georgia
• California agencies kept data longer than necessary and shared it with unauthorized agencies
• Police in San Diego County broke the law sharing drivers’ data

The negligent use of ALPRs has led to dangerous police encounters, including pulling guns on innocent drivers. A few examples:

• San Francisco woman pulled out of her car at gunpoint because of a license plate reader error
• Cops terrorize a Black family, then blame the license plate reader for misidentifying a “stolen” vehicle
• Deputies sued after a false ALPR hit led to a guns-out traffic stop of a California privacy activist
• A Denver woman had to prove her innocence after detectives relied on Flock cameras to pin a $25 package theft on her.

ALPRs are more likely to surveil communities with a higher density of Black and brown people, reinforcing systemic racism in policing.

The Electronic Frontier Foundation reviewed the Oakland Police Department’s use of ALPRs and found cameras were more likely to scan plates in communities with a higher density of Black and brown people. After 9/11, the NYPD used ALPRs to monitor Muslims visiting mosques.

“In the first 10 months of their use, 84% of the drivers stopped by Oak Park police because of Flock were Black.” — Freedom to Thrive Oak Park

Police agencies frequently share ALPR data with ICE, putting undocumented people at risk — even in states where this is legally prohibited:

• ICE taps into Flock’s nationwide camera network, data shows
• Police in Pasadena and Long Beach pledged not to send plate data to ICE — then shared it anyway
• Documents reveal ICE using driver location data from local police for deportations
• Data sharing with federal immigration agencies might violate Washington law

No. Police have always had methods to obtain location information for suspects of crimes. These methods used to require establishing probable cause and obtaining a search warrant, which provides oversight and accountability as required by the 4th Amendment. ALPRs, on the other hand, collect location data on all of us, and they are searched without any warrants or oversight.

1. You don’t get to decide what looks suspicious tomorrow. Just because you’re not doing anything wrong today doesn’t mean you won’t be watched tomorrow. Cameras like Flock don’t know your intentions — only your movements. A trip to a protest, a friend’s house in a “high-crime” area, or even a misread plate can flag you as “suspicious.” When governments or third parties gain unchecked surveillance powers, they’re eventually used against people who weren’t doing anything wrong — until someone decided they were.

2. Mistakes happen, and you’re the one who pays for them. ALPRs are not always accurate. People have been pulled over at gunpoint, arrested, or detained because a camera misread a plate or flagged the wrong car. If you “have nothing to hide,” you also have nothing to correct the record with when a machine error points the finger at you.

No, ALPRs record all vehicles that pass by, not just those involved in crimes. They capture license plates, unique identifying features, locations, dates, and times of every vehicle, regardless of whether the driver is suspected of wrongdoing. That data can also be shared with other agencies and third parties, extending this surveillance far beyond your community.

No, police do not need a warrant to search these cameras. The data is owned by the police department, and agencies can access it without a warrant. There is often no oversight at all on how these searches are conducted, raising concerns about their constitutionality under the Fourth Amendment. Agency ALPR policies often become meaningless once an agency opts into a data-sharing network — with tens of thousands of national searches occurring daily.

There is little to no oversight. Some departments have ALPR policies, but they are often weak and poorly enforced — and many agencies have none at all, with no requirement for transparency or accountability. Flock offers a “transparency portal,” but customers can cherry-pick what’s included, and the data is often incomplete or misleading.

Absolutely not. Flock’s transparency portals are notoriously incomplete and often misleading, letting agencies cherry-pick what’s shown. Boulder, Colorado’s portal listed around 90 agencies with access — but a public-records request revealed that over 6,000 agencies actually had access.

There’s good reason for doubt. In November 2025, a security researcher found Flock logins for sale on Russian hacking forums, as Flock did not require multi-factor authentication. Flock has also been caught misrepresenting who can access its data — including federal access to ALPR systems that the company initially denied.

Several U.S. cities have killed ALPR contracts, including Denver and Austin. An effective strategy is to raise concerns in your community, build a group of advocates, and petition your council not to approve or renew the contract. See our Get Involved page to start.