If you drive in the city of Binghamton, the police department likely knows you've been there.

Some Binghamton police cars are among the law enforcement vehicles in the region now equipped with license plate readers that take pictures of thousands of license plates every day.

The high-tech devices operate silently, recording date, time and location of each vehicle passing by the police car.

The information can be downloaded from a computer in the police car so it can be stored and analyzed in the future.

According to the American Civil Liberties Union, vast amounts of data are collected by agencies around the United States.

The ACLU has been collecting information on state and local policies regarding the use of information from license plate readers. The organization contends there's a need for limits on the utilization of plate readers.

Binghamton police use the Mobile Plate Hunter - 900, sold by ELSAG North America. The company says the unit can alert a police officer within milliseconds if a vehicle registration is in a database.

The company claims the device can capture up to 1800 plate reads per minute, even at night.

Binghamton police chief Joseph Zikuski could not be reached for comment on the department's use of license plate readers or the policies regarding the retention of information collected by the Mobile Plate Hunters.