The New York Civil Liberties Union Tuesday sent the NYPD and transportation agencies requests for the city and state records to determine if E-Z Pass readers are being used to track drivers outside toll areas.

The records request was filed after the NYCLU created a video of its lawyer, Nate Vogel, driving around Manhattan with a device created by an anonymous privacy activist that detects E-Z Pass readers.

The device, which looks like a small toy cow mounted on a dashboard, was "going off almost constantly during a drive through Midtown and Lower Manhattan -- in areas free of toll collection booths," the NYCLU said in its release.

"New Yorkers have a right to know if their use of toll-paying technology is secretly being used to track their innocent comings and goings," said NYCLU Executive Director Donna Lieberman.

New York City Department of Transportation spokesman Nicholas Mosquera said the readers collect "scrambled" aggregate traffic information that does not identify individual motorists.

"This technology, which is also in use in municipalities throughout the region and the nation, has contributed to significant travel time improvements," Mosquera said.

Representatives from the NYPD and state Department of Transportation did not return requests for comment.