As of December 1, 2013, Michigan drivers have to buy new license plates every 10 years. One of the reasons offered in support of this new requirement is that it will ensure plates are legible enough to be read by automatic license plate recognition (ALPR) technology. The Senate Fiscal Analysis noted that this technology was credited with assisting law enforcement in identifying the Boston Marathon bombers in 2013 as well as the man behind the attempted 2010 Times Square car bombing.
How does this technology work? Cameras for the ALPR technology are attached to police vehicles or at static locations such as entrances and exits of parking structures, on streetlights, or under overpasses. The cameras often use both infrared and visual light so they can record day and night. Images of thousands of vehicles can be captured over a very short period of time. Using algorithms, the technology isolates the numbers on the plate of each vehicle. The image of the vehicle, the plate numbers, and the GPS location of the vehicle can then be stored in a database. These databases are maintained by government agencies and also by the private companies providing the technology.
Some people have voiced privacy concerns. “Creepy” is a word often used when I discussed this technology with coworkers, friends, and family. An ACLU-Massachusetts blog noted: “The more information available to these systems, and the longer the data is kept, the more the government and corporations are able to tell about our private lives. Just imagine: police can station an ALPR camera at an address or building of interest and without much human effort compile a very accurate guest list for any event or occasion.”
Because of these privacy concerns, some states have all but banned the technology while others have restricted the length of time data can be stored. House Bill 4981, introduced here in Michigan in September 2013, would require plate numbers to be purged after 48 hours with some exceptions. Balancing the ability of the law enforcement to protect against the public’s interest in privacy is a laudable but challenging goal. As the executive director of the Michigan Sheriff’s Association is reported as saying: “The devil’s going to be in the details.”