EFF: Police should need a warrant to search license plate reader data
The Electronic Frontier Foundation, in a post co-written with legal intern Andi Cao, argues that automated license plate readers are mass surveillance and that cities should not buy them. Where they already operate, EFF says courts and legislatures should at minimum require police to get a warrant before searching stored data. A warrant would make an officer show a judge probable cause and describe what is being searched, rather than letting the officer decide alone.
The post leans on San Jose, where EFF and the ACLU of Northern California represent two groups in a lawsuit over the practice. SJPD officers searched stored data 261,711 times between June 2024 and June 2025, about 692 a day, and the department fired an officer who tracked a woman and passed her location to his cousin, the man she had accused of domestic violence. EFF also lists searches aimed at Romani people, protesters and an abortion, plus thousands of searches run on behalf of federal immigration enforcement, and says a judge should have refused to sign off on each one. It notes that a federal judge in Oklahoma recently agreed that a warrant is required. EFF concludes that a warrant requirement would not make the systems acceptable, but would stop much casual and abusive searching.
CounterpointEFF is an advocacy group that wants the systems abolished. Police agencies and vendors such as Flock have argued that plate readers help solve vehicle thefts and violent crimes, and that plates on public roads carry little expectation of privacy. Law enforcement groups would add that a warrant requirement slows time-sensitive investigations.