The American Civil Liberties Union announced Wednesday that Americans are being subjected to hidden-in-plain-sight surveillance of their car movements by mobile and stationary license plate scanners.
Localized controversies previously called attention to police use of the scanners, which can photograph hundreds of license plates in a policeman's shift with timestamps and location, but the ACLU's report notes that the issue is indeed national in scope.
Hundreds of millions of records are pouring into local, state and even regional databases, the report says, and only five states – Arkansas, Maine New Hampshire, Utah and Vermont – have restrictions on the scanners. Some police departments store the records indefinitely.
In Maryland, 85 million license plate records were sent to the state's data fusion center in 2012, the report says, of which just 0.2 percent were flagged for possible violations of the law. Ninety-seven percent of the detected violations were for suspended or revoked registrations or failure to comply with state emissions testing.
In 250,000-person Jersey City, N.J., police captured 2.1 million plate records in 2012.
All police license scanner records are not necessarily fed into state or regional databases, the report says, but there are many unknown details. Even in cases where the information is not sent to large agencies to review, there can be privacy issues.
"The potential privacy harms discussed in this report are not merely theoretical," the report says, pointing to the easily accessible information about Rybak as a warning about the potential of massive on-demand surveillance without proper restrictions.
The ACLU notes that police departments and states have vastly different regulations on the use of license plate scanners. Of the jurisdictions that responded to ACLU information requests, Yonkers, N.Y., indicated it keeps the records indefinitely, while New Jersey keeps them for five years. Several cities - including Boston, Mass., and Raleigh, N.C. - require destruction of the records in less than one year.
"The spread of these scanners is creating what are, in effect, government location tracking systems recording the movements of many millions of innocent Americans in huge databases," said ACLU Staff Attorney Catherine Crump in a released statement. "We don't object to the use of these systems to flag cars that are stolen or belong to fugitives, but these documents show a dire need for rules to make sure that this technology isn't used for unbridled government surveillance."
It's unclear exactly how much of the information procured by scanners is obtained and stored by the federal government.
The ACLU is suing the Department of Justice, the Department of Homeland Security and the Department of Transportation for information on their use of license plate readers, according to the report. Currently, the civil liberties group said, U.S. Customs and Border Protection and the Drug Enforcement Administration use the devices along the nation's borders.
In June, former National Security Agency contractor Edward Snowden revealed that the agency had been collecting the phone records of Americans for years, and that the NSA has the ability to monitor Internet activity. The ACLU called the car-record collection "the most widespread location tracking technology you've probably never heard of" in a blog post.