PIEDMONT, CALIFORNIA—In the early 20th century, a group of wealthy people on unincorporated land chose not to join nearby Oakland, and instead decided to found the city of Piedmont. Large, stately homes and a handful of businesses defined the city. Today, the town-on-the-hill has only 11,000 residents.

Today, Piedmont is entirely surrounded by Oakland, and is one of the few towns in America to be entirely contained within another city. Despite the recent efforts of a small group to “Liberate Piedmont” and "return" it to Oakland, it’s likely going to stay this way.

But if the local police chief has her way, Piedmont will become even more unique. The chief is pushing for Piedmont to become one of the few cities in America to install automatic license plate readers (LPR) at its city borders—in this case, they would be mounted above each of the 30 roads leading into town. If successful, Piedmont would be the second wealthy Bay Area community with such a system. (Tiburon, in nearby Marin County, approved LPRs more than three years ago for the only two roads leading into and out of town. Sugar Land, Texas, approved similar measures for its municipal borders in November 2012.)

“I think there's a good chance we will do it to some level,” Rikki Goede, the police chief, told Ars on Monday. “It's an investigative tool being used as a force-multiplier. That's what tech is all about, helping us be more efficient and at the end of the day, keeping our communities safe. If technology can help with that, we should be for that.”

As in Tiburon, Piedmont’s proposed system could create a de facto electronic border fence around the city. It would scan the license plate of every car going into or out of town and retain that information for a year. However, the LPR data would also be transferred “nearly instantaneously” to the Northern California Regional Intelligence Center (NCRIC), which feeds law enforcement intelligence to the federal government.

The Piedmont Police Department is currently awaiting a proposal from PIPS, a leading LPR vendor, and hopes to present that plan to the city government in the coming months. The PPD already has one mobile LPR, positioned on a patrol car.

As we reported last year, Federal Signal Corporation (FSC), which sells LPRs under its PIPS brand name, says it has sold 20,000 mobile systems across North America and another 15,000 fixed devices across the United States and the United Kingdom.

"We work with the 25 largest cities in the United States, over 100 cities in the US and over 200 in North America, including the Royal Canadian Mounted Police and in Mexico," said Tim O'Leary, a company vice president, in an interview with Ars in 2012. "We think the market is growing at eight to 10 percent, adjusted growth rate, annually."

In a filing with the Securities and Exchange Commission in 2012, FSC said its sales of LPRs were up by $2.1 million in 2010 alone.

Piedmont has budgeted $5.4 million for its police force this fiscal year (PDF). Assuming 60 cameras for 30 roads at an average of $14,000 per camera, that would work out to $840,000 in purchasing costs alone.

Burglaries on the rise

As we reported last year, the scanners can read 60 license plates per second, then match observed plates against a "hot list" of wanted vehicles, stolen cars, or criminal suspects. LPRs have increasingly become a mainstay of law enforcement nationwide. Many law enforcement agencies tout them as a highly effective "force multiplier" for catching bad guys, most notably burglars, car thieves, child molesters, kidnappers, terrorists, and—potentially—undocumented immigrants.

Today, tens of thousands of LPRs are being used by law enforcement agencies all over the country—practically every week, local media around the country report on some LPR expansion. But the system's unchecked and largely unmonitored use raises significant privacy concerns. License plates, dates, times, and locations of all cars seen are kept in law enforcement databases for months or even years at a time. In the worst case, the New York State Police keeps all of its LPR data indefinitely. No universal standard governs how long data can or should be retained.

So what worries Piedmont enough to call for LPRs? Burglaries.

Chief Goede said the number of burglaries jumped from 90 in 2011 up to 135 in 2012. While that may be peanuts compared to what she experienced in her last job as assistant police chief of the San Jose Police Department (and its population of nearly 1 million), it’s still important for a community like Piedmont.

“You have to keep in mind, what Tiburon can do and Piedmont can do—San Jose can't do [because of its size and financial constraints.]” Still, she didn’t think that LPRs would instantly solve Piedmont’s problems. She sees them as part of the “three prongs” of good policing.

“You've got to have a good well-staffed police department that does problem solving,” she said. “You’ve got to have community collaboration, and a community that's invested in the community and calls the police and reports suspicious activity. The third is technology. Those three are what creates a safe community. One's not going to get rid of the other, they have to be equally strong.”

Civil liberties lurk in the background

Not surprisingly, the expanded use of LPRs has drawn the ire of privacy watchdogs. In late July 2012, the American Civil Liberties Union and its affiliates sent requests to local police departments and state agencies across 38 states to request information on how LPRs are used.

Part of the fear is that a police officer could potentially have a substantial record of movement for specific cars moving in and out of the city.

Goede said that for now, her department had not consulted with any civil liberties groups such as the American Civil Liberties Union or the Electronic Frontier Foundation. She acknowledged that it was a “challenge” to balance the two concerns.

“ALPR cameras can be used with minimal impact on individual liberties, but they can also be used to record each time a visitor or resident enters or exits a city, retain that information indefinitely, allow that information to be used without restrictions or oversight, and even share that information with other agencies in order to build a robust profile of an individual’s whereabouts, activities, and associations,” said Chris Conley, a staff attorney at the American Civil Liberties Union.

“We would be happy to talk with the Piedmont police department to discuss the costs as well as the benefits of an ALPR system, and to encourage the department to establish policies and safeguards that recognize the potential impact on individual privacy of ALPR prior to purchasing or using cameras.”

Still, Chief Goede feels confident that her department would impose adequate privacy restrictions to keep the LPR database from being abused. She said this includes limiting access to such data for criminal investigations only.

"[But] communities are not going to just want technology to make them safer, they're going to demand that we use technology to make them safer,” she added.