After the city of San Leandro purchased a license plate reader for its Police Department in 2008, computer security consultant Michael Katz-Lacabe asked the city for a record of every time the scanners had photographed his car.

The results shocked him.

The paperback-size device, installed on the outside of police cars, can log thousands of license plates in an eight-hour patrol shift. Katz-Lacabe said it had photographed his two cars on 112 occasions, including one image from 2009 that shows him and his daughters stepping out of his Toyota Prius in their driveway.

That photograph, Katz-Lacabe said, made him "frightened and concerned about the magnitude of police surveillance and data collection." The single patrol car in San Leandro equipped with a plate reader had logged his car once a week on average, photographing his license plate and documenting the time and location.

At a rapid pace, and mostly hidden from the public, police agencies throughout the state have been collecting millions of records on drivers and feeding them into intelligence fusion centers operated by local, state and federal law enforcement.

With heightened concern over secret intelligence operations at the National Security Agency, the localized effort to track drivers highlights the extent to which the government has committed to collecting large amounts of data on people who have done nothing wrong.

A year ago, the Northern California Regional Intelligence Center - one of dozens of law enforcement intelligence-sharing centers set up after the terrorist attacks of Sept. 11, 2001 - signed a $340,000 agreement with the Silicon Valley firm Palantir to construct a database of license plate records flowing in from police using the devices across 14 counties, documents and interviews show.

The extent of the center's data collection has never been revealed. Neither has the involvement of Palantir, a Silicon Valley firm with extensive ties to the Pentagon and intelligence agencies. The CIA's venture capital fund, In-Q-Tel, has invested $2 million in the firm.

100 million records

The jurisdictions supplying license-plate data to the intelligence center stretch from Monterey County to the Oregon border. According to contract documents, the database will be capable of handling at least 100 million records and be accessible to local and state law enforcement across the region.

Law enforcement agencies from throughout Northern California will be able to access the data, as will state and federal authorities.

In the Bay Area, at least 32 government agencies use license-plate readers. The city of Piedmont decided to install them along the border with Oakland, and the Marin County enclave of Tiburon placed plate scanners and cameras on two roads leading into and out of town.

Law enforcement agencies from throughout the region also have adopted the technology. Police in Daly City, Milpitas and San Francisco have all signed agreements to provide data from plate readers to the Northern California Regional Intelligence Center. A Piedmont document indicates that city is also participating, along with Oakland, Walnut Creek, Alameda and the California Highway Patrol.

Too many details?

Katz-Lacabe believes the records of his movements are too revealing about someone who has done nothing wrong. With the technology, he said, "you can tell who your friends are, who you hang out with, where you go to church, whether you've been to a political meeting."

Lt. Randall Brandt of the San Leandro police said, "It's new technology, we're learning as we go, but it works 100 times better than driving around looking for license plates with our eyes."

The intelligence center database will store license plate records for up to two years, regardless of data retention limits set in place by local police departments.

Uses vary

Many cities use license-plate readers to enforce parking restrictions or identify motorists who run red lights. Police in New York City have used the readers to catch car thieves and scan parking lots to identify motorists with open warrants.

Long Beach police detectives used scanner data to arrest five people for a 2010 homicide. Plate readers in Tiburon identified celebrity chef Guy Fieri's yellow Lamborghini in March 2011, which allegedly had been stolen from a San Francisco dealership by a teenager who embarked on a crime spree two years ago and now faces attempted murder charges.

Sid Heal, a retired commander with the Los Angeles Sheriff's Department, oversaw the adoption of plate readers in his agency in the mid-2000s. Heal recalled the dramatic uptick the plate readers made in the auto-theft unit's productivity.

"We found 10 stolen vehicles on the first weekend in 2005 with our antitheft teams," Heal said. "I had a hit within 45 minutes."

Before, Heal said, police had to call license plates in to a dispatcher and wait to have the car verified as stolen. Plate readers, Heal said "are lightning fast in comparison" and allow officers to run up to 1,200 plates an hour, as opposed to 20 to 50 plates per day previously.

But Jennifer Lynch, a staff attorney at the Electronic Frontier Foundation, said the Northern California database raises significant privacy concerns. "Because so many people in the Bay Area are mobile, it makes it that much more possible to track people from county to county," Lynch said.

Then-state Sen. Joe Simitian introduced a bill last year that would have required California police to purge license plate data after 60 days and applied the rule to companies that collect such data. Law enforcement and private businesses involved in the technology resisted, and the bill died.

'Fundamental question'

"Do we really want to maintain a database that tracks personal movements of law-abiding citizens in perpetuity? That's the fundamental question here," said Simitian, now a Santa Clara County supervisor. "Larger and larger amounts of data collected over longer periods of time provide a very detailed look at the personal movements of private citizens."

Heal said that absent clear legal limits on license plate readers, law enforcement agencies will continue to expand their ability to gather such information.

"A lot of the guidance on this technology - the court doctrine - is nonexistent," Heal said. "Until that guidance comes, law enforcement is in an exploratory mode."

The independent, nonprofit Center for Investigative Reporting is the country's largest investigative reporting team. For more, visit www.cironline.org. E-mail: info@cironline.org