The Department of Homeland Security plans to build a national database that would gather information from license-plate readers that scan every vehicle crossing their paths, according to a solicitation last week from the agency.
U.S. Immigration and Customs Enforcement would use the technology to help locate and arrest absconders and criminal aliens, reducing surveillance hours and enhancing officer safety, according to the request.
DHS spokeswoman Gillian Christensen told Ars Technica that the database could only be accessed in conjunction with ongoing criminal investigations.
License-plate readers, which automatically record information on all vehicles that cross their paths instead of just suspect vehicles, are controversial among privacy advocates. The American Civil Liberties Union issued a report last year criticizing the increased use of such devices, saying they collect vast amounts of data on innocent individuals and could be used for abusive tracking and targeting.
More and more cameras, longer retention periods, and widespread sharing allow law enforcement agents to assemble the individual puzzle pieces of where we have been over time into a single, high-resolution image of our lives, the ACLU said.
The group has argued that constant monitoring can chill the exercise of our cherished rights to free speech and association.
Despite concerns about automatic license-plate readers, the use of such devices has grown in recent years, in large part due to millions of dollars in grants from Homeland Security and the Justice Department to state and local law-enforcement agencies.
A 2011 survey of 70 police agencies by the Police Executive Research Forum found that nearly three-quarters of the departments were using license-plate readers and 85 percent planned to increase their use of the devices.
The Homeland Security plan comes amid increased concerns about the governments sweeping domestic surveillance programs, which came under heightened scrutiny following leaks last year from former National Security Agency contractor Edward Snowden.