Flock

Judge Says Warrantless Flock Search Violated Driver's Fourth Amendment Rights

The automated license plate reader system is “a type of indiscriminate mass surveillance," says a federal judge.

Elizabeth Nolan Brown | 10.7.2026 11:45 AM

Share on FacebookShare on XShare on RedditShare by emailPrint friendly versionCopy page URL Add Reason to Google

Media Contact & Reprint Requests

(Matt Kaminsky/ZUMAPRESS/Newscom/Midjourney.)

Today, there's yet more evidence that the tide is turning against Flock, an automated license plate reader (ALPR) system in pervasive use around the country. Calling it "indiscriminate mass surveillance," a federal court in Oklahoma granted a woman's motion to suppress evidence found in her car after a search that was conducted based on information obtained through Flock.

The court's scathing and beautiful takedown of warrantless Flock searches is something to behold.

"Think about it this way. We might reasonably expect our friends and family to tell us something like: 'Hey, I saw you out driving by the store last week,'" writes Judge Sara E. Hill of the U.S. District Court for the District of Oklahoma. "But we do not expect people we know—let alone strangers, and especially not law enforcement—to randomly approach us to say: 'Hey, I have been following your car for the last 30 days, and here is a detailed log of every place your vehicle has been with supporting photographic evidence. I am also going to share this information with law enforcement throughout the country so they know your whereabouts, too.'"

You are reading Sex & Tech, from Elizabeth Nolan Brown. Get more of Elizabeth's sex, tech, bodily autonomy, law, and online culture coverage.

Name

This field is for validation purposes and should be left unchanged.

Email(Required)

SUBSCRIBE

"Freedom from persistent, dragnet-style surveillance while in public…is a reasonable expectation," adds Hill, rejecting previous court holdings that law enforcement using automated license plate reader systems are not "searches" for Fourth Amendment purposes.

The 4th Amendment Quandary

The Flock system—and similar programs—capture images of people's cars and store these images along with the time and location they were captured and details about the car's make, model, and various other features. Authorities can later query the system about specific vehicles (using license plate number or description) or to search for all vehicles that drove in a given area at a given time.

High-profile instances of cops using Flock for stalking purposes have made news. But the bigger issue is how these tools are being used in legitimate cases: without warrants. And often without reasonable suspicion.

The protocol that has emerged around ALPR systems does not involve cops presenting probable cause and obtaining a warrant before conducting a search.

This protocol seems to be in direct opposition to the Fourth Amendment. But at least one federal court has already given this its blessing. In September, the U.S. District Court for the Central District of California held that querying the Flock database is not a "search" for Fourth Amendment purposes. According to Judge Virginia A. Phillips, no probable cause or particularized warrant is required before cops conduct a search.

It's reassuring to see the U.S. District Court for the District of Oklahoma come to a very different conclusion than the California court did.

The Traffic Stop

The current case concerns the Tulsa County Sheriff's Office and Deputy Sheriff Freddie Alaniz. After an ALPR system on his car noticed a car with a California license plate drive by on........

© Reason.com