Americans are being tracked every day. If you own a vehicle, you are being tracked by law enforcement. Automatic license plate readers, mounted on police cars or on objects like road signs and bridges, use small, high-speed cameras to photograph thousands of plates per minute.

In July 2012, America Civil Liberties Union affiliates in 38 states and Washington, D.C. sent Public Records Act requests to almost 600 local and state police departments, as well as other state and federal agencies, to obtain information on how these agencies use license plate readers. In response, the ACLU received 26,000 pages of documents detailing the use of the technology around the country.

According to the ACLU, automatic license plate readers capture high speed passing license plates with software that analyzes photographs to identify plate numbers. The official rationale is that license plate readers are used to check for stolen vehicles, to aid in determining whether a vehicle has been used in the commission of a crime, or during AMBER alerts, among other uses.

However, automatic license plate readers have the potential to create permanent records of virtually everywhere any of us has driven, radically transforming the consequences of leaving home to pursue private life, and opening up many opportunities for abuse. The tracking of peoples’ locations constitutes a significant invasion of privacy, which can reveal many things about their lives, such as what friends, doctors, protests, political events, or churches a person may visit.

Source: “You are Being Tracked: How License Plate Readers Are Being Used to Record American’s Movement”, American Civil Liberties Union (ACLU) July, 2013, https://www.aclu.org/files/assets/071613-aclu-alprreport-opt-v05.pdf.

Student Researcher: Sierra Smith (Sonoma State University)

Faculty Evaluator: Diana Grant (Sonoma State University)

Review Article with Credder