Cars drive toward the outbound entrance of the Holland Tunnel.
Cars drive toward the outbound entrance of the Holland Tunnel. - 
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The American Civil Liberties Union says it has found another instance of Americans being tracked by the government. Not online, but on the road through license plate tracking.

"We found that police departments all over the country are using these very powerful license plate readers," says Kade Crockford, director of the ACLU's Technology and Liberty project. "These records are not simply images of our cars and our license plates, they also include where we were and when."

The ACLU combed through 26,000 pages of documents from police departments. The information includes location bits, time stamps -- more of that so-called meta data that was at the center of the NSA leaks. And the ACLU says all this license information getting sucked up by bridge, tunnel and toll booth cameras doesn't get thrown out by the police. Another parallel to online surveillance, according to Crockford.

"Police are making the same argument with respect to this location information, they are saying we need to keep this data for a long period of time because it might be useful to us sometime down the road

Crockford says there should be a limit to how long law enforcement can keep license plate tracking data. And that drivers should be made aware it's being collected in the first place.

Follow Ben Johnson at @@TheBrockJohnson