The American Civil Liberties Union (ACLU) of Vermont has called on local law enforcement agencies to disclose how they're using, sharing and storing data gathered automatically from passing motorists on Vermont's highways.

This week, the ACLU of Vermont joined affiliates in 34 other states in requesting information on police use of automated license plate readers, or ALPRs. The use of ALPRs in Vermont was first reported in a December 8, 2010 Seven Days cover story, "Digital Apprehensions: High-tech computer crime fighting has arrived in Vermont — but at what price?"

ALPRs are digital devices mounted on patrol cars or stationary objects along roadways, such as telephone poles and highway overpasses, that scan every license plate that enters their fields of view. An ALPR, which is capable of scanning several thousand license plates per hour, is connected to a computer in the patrol car that alerts the officer whenever it gets a "hit." The technology can be used to identify drivers who are runaways, have outstanding warrants, are driving under suspended or revoked licenses, or have recently fled the scene of an accident or crime.

Although ALPRs are still believed to be in limited use in Vermont — as of 2011, only six law enforcement agencies in the state had them — they have been used successfully to fight crime. The St. Albans Police, for example, working with the Vermont Fusion Center in Williston, used one in 2010 to nab a suspect believed to be responsible for a series of armed bank robberies in Franklin County in 2009.

But despite such successes, the use of this digital crime-fighting tool raises inevitable questions about citizens' privacy and Fourth Amendment rights. Groups such as the ACLU and the Electronic Frontier Foundation have expressed growing concern that these and similar technologies, such as GPS locators in smart phones and digital tablets, are moving us toward a total surveillance society. They warn that ALPRs have been deployed rapidly across the country, with little or no public debate or input into how the data is used.

One major question, says Allen Gilbert, executive director of the ACLU of Vermont, is the extent to which local police departments are pooling the information and uploading it to state, regional or federal databases. The ACLU is looking to find out if ALPRs are being used as a tool for routine location tracking and surveillance and to collect and store information not just on people suspected of crimes but on all motorists.

This week, the ACLU-VT sent three records requests to government agencies. The first went to the Homeland Security Unit of the Vermont Department of Public Safety. DPS receives federal grants from the U.S. Department of Homeland Security, which funds many ALPR systems. The request asks for: information about how federal grant money is used to pay for ALPR systems, which municipalities in Vermont have received federal grants for ALPR systems and how ALPR data is shared outside the state.  Because the ACLU of Vermont believes that nearly a dozen Vermont cities and towns already have the systems, the request will fill out public knowledge of where ALPR systems are being used and how Vermonters’ movement data is handled.

"The bigger question is, are we building a nationwide surveillance system based around the tracking of license plates?" Gilbert asks. "It's just one more way for the government to know people's whereabouts at any of a number of times."

To date, the ACLU has received no response to his records requests but expects to later this week.

Photo courtesy of ELSAG North America, which manufactured ALPRs used in Vermont.