TRACKING AND MONITORING
Automated License Plate Readers (ALPRs) are high-speed, computer-controlled camera systems that are typically mounted on street poles, streetlights, highway overpasses, mobile trailers, or attached to police squad cars. ALPRs automatically capture all license plate numbers that come into view, along with the location, date, and time. The data, which includes photographs of the vehicle and sometimes its driver and passengers, is then uploaded to a central server.
The information is collected and used by police to find out where a plate has been in the past, to determine whether a vehicle was at the scene of a crime, to identify travel patterns, and even to discover vehicles that may be associated with each other. This information can then be shared with thousands of other agencies of all sorts.
ALPR data can paint an intimate portrait of a driver’s life and even chill First Amendment protected activity. ALPR technology can be used to target drivers who visit sensitive places such as health centers, immigration clinics, gun shops, union halls, protests, or centers of religious worship. It’s particularly disturbing that automatic license plate readers track and record the movements of millions of ordinary people, even though the overwhelming majority are not connected to a crime.
ALPR is a powerful surveillance technology that can be used to invade the privacy of individuals as well as to violate the rights of entire communities. Law enforcement agencies have abused this technology. Police officers in New York drove down a street and electronically recorded the license plate numbers of everyone parked near a mosque. Police in Birmingham targeted a Muslim community while misleading the public about the project. ALPR data obtained from the Oakland Police Department showed that police disproportionately deploy ALPR-mounted vehicles in low-income communities and communities of color.
Officers have abused law enforcement databases, including license plate information and records held by motor vehicle departments. In 1998, a Washington, D.C. police officer “pleaded guilty to extortion after looking up the plates of vehicles near a gay bar and blackmailing the vehicle owners.” Police officers have also used databases to search romantic interests in Florida. A former female police officer in Minnesota discovered that her driver’s license record was accessed 425 times by 18 different agencies across the state.
In addition to deliberate misuse, ALPRs sometimes misread plates, leading to dire consequences. In 2009, San Francisco police pulled over Denise Green, an African-American city worker, handcuffed her at gunpoint, forced her to her knees, and searched both her and her vehicle—all because her car was misidentified as stolen due to a license plate reader error. Her experience led the U.S. Ninth Circuit Court of Appeals to rule that technology alone can’t be the basis of such a stop, but that judgment does not apply everywhere, leaving people vulnerable to similar law enforcement errors.
Law enforcement agencies without their own ALPR systems can access data collected by other law enforcement agencies through regional sharing systems and networks operated by these private companies. Several companies operate independent, non-law enforcement ALPR databases, contracting with drivers to put cameras on private vehicles to collect the information. These data are then sold to companies like insurers, but law enforcement can also purchase access to this commercial data on a subscription basis.