ACLU Warns ALPRs and AI Tools Are Being Used to Flag Drivers for 'Suspicious' Travel

The American Civil Liberties Union warned Monday that law enforcement agencies across the United States are increasingly using automated license plate readers and AI-powered tools to pull over drivers who are not suspected of a specific crime. The group says the tools are now being used to flag supposedly "suspicious" driving patterns, and it points to the case of a Virginia woman stopped during a road trip. The ACLU says encounters like hers could become more common.

Knowles' roadside stop

Grace Knowles, a woman in her 20s from northern Virginia, took a road trip through Oregon, Texas and Louisiana in September 2025. On her way to Florida, she was pulled over by an officer who said she had spent too much time driving in the left lane. The officer questioned her about her travels and asked for proof that she had been in New Orleans. He later identified himself as a special agent with the FBI who was on a project for human and drug trafficking, and he told her that her license plate had been flagged for suspicious travel patterns.

After she convinced him she was just on a road trip, he offered to show her what he was looking at on a computer in his car. Knowles told the ACLU it was basically a heat map of the United States, with circles where she had been, and that clicking one showed a photo of her license plate. When she asked how authorities had collected images of her license plate, the officer told her the cameras were everywhere, including on top of highway signs.

Wider concerns and other cases

Jay Stanley, a senior policy analyst with the ACLU, wrote that for many people those encounters will be far more fraught, frightening and dangerous than what Knowles experienced.

Knowles' story is far from the only case raising concerns. In March, The Markup reported that a California grandmother was questioned by U.S. Customs and Border Protection officers about how often she visited local casinos. In another case, a man was targeted for a traffic stop after repeatedly driving back and forth between Wisconsin and Michigan, which local police described as "a known source State for Marijuana."

Earlier this month, a federal jury in Texas sided with a man who sued over what his attorneys described as an "unconstitutional traffic stop scheme" enabled by "AI-powered" license plate readers. According to the lawsuit, he was pulled over after his license plate was flagged for driving from Houston to Carrizo Springs, staying overnight, and returning home the following day. WIRED reported this month that Flock had developed an AI-powered investigative tool that "can identify drivers and track vehicles by their patterns of movement alone."

Growing pushback

ALPRs are already facing growing backlash. Companies such as Flock Safety and Axon have become known in recent years for selling ALPR systems to law enforcement. The systems scan license plates as vehicles pass, collecting vehicle information along with the time and location they were spotted, and police can search that data during investigations.

Privacy advocates warn that the cameras collect location data on millions of people who are not suspected of crimes, often without a warrant, probable cause, or reasonable suspicion. There have also been reports of the systems leading to mistakes and misuse by law enforcement. An August YouGov survey found that 46% of respondents opposed law enforcement using the technology in their communities, while 38% supported it. Law enforcement agencies around the country, including the Los Angeles Police Department, have suspended or even ended their Flock contracts amid the growing backlash. Flock did not immediately respond to a request for comment.

Earlier coverage: Flock CEO Says Anti-Flock Backlash Is Not Real, Leaked Audio Shows · Federal Judge Rules Flock Search Was ‘Indiscriminate Mass Surveillance’ and Unconstitutional

Sources: Gizmodo · Tom's Hardware · ACLU