People who drive around San Carlos won’t have their license plate numbers automatically read.

That’s what the City Council decided Monday night on a 3-2 vote driven by concern over how data collected would be used and safeguarded.

The San Mateo County Sheriff’s Office asked the city to buy two license-plate readers at an estimated cost of about $70,000. Its request was backed by Police Chief Greg Rothaus and City Manager Jeff Maltbie.

One camera could be mounted on a patrol vehicle and the other stationed at the Brittan Avenue onramp to southbound Highway 101, near Industrial Road and a business area that has seen more than 70 auto or commercial thefts in the last 12 months, according to Rothaus. The highway ramp is a “quick way to commit a crime and get out of town,” he said.

Councilman Matt Grocott, who voted against the proposal along with Mayor Mark Olbert and Vice Mayor Ron Collins, said installing a fixed camera would be akin to “setting up a trap” and using data to presume a driver is guilty until proven otherwise.

“I respect law enforcement,” Grocott said. “But I respect our liberty more.”

Collins agreed.

“If we’re going to do surveillance, it ought to be targeted,” the vice mayor said. “It’s getting awfully close to big brother.”

Councilman Bob Grassilli acknowledged that he had mixed feelings. A camera at the Brittan onramp makes “some sense,” he said, but “the mobile one is harder for me.” Grassilli said he nevertheless supports seeking bids because they could “give us another chance to think about it.”

Councilman Cameron Johnson said he favors license plate readers because they are “about making something that law enforcement already does more effective. … For me it’s just about giving law enforcement one more tool in the arsenal.”

The high-speed cameras can scan license plate numbers from passing vehicles into a law enforcement database to see whether they match plate numbers connected to crimes. The numbers would be kept in that database, along with information about where the plates were spotted.

When there’s a rash of burglaries, “people in this town are up in arms” and expect the city to ensure their safety and protect their property, City Manager Maltbie told the council.

“I remind the council that license plates don’t belong to individuals, they belong to the public,” he said. “There is no perception of privacy when you’re driving down the street.”

Olbert said he doesn’t believe data collected in the city should be warehoused for a year in the Northern California Regional Intelligence Center, where a government-sponsored database is kept. The mayor said he would have been more “amenable” to the idea if the information is kept for a much shorter time, such as 90 days.

“Centralizing data makes it a rich target to go after,” Olbert said, pointing to the unauthorized surveillance by National Security Agency employees revealed by whistleblower Edward Snowden.

“That’s human nature,” Olbert said, adding that surveillance is “a powerful tool that also has the power to abuse.”

The Sheriff’s Office is talking with other San Mateo County communities about using automated license plate readers, Deputy Rebecca Rosenblatt wrote in an email Tuesday.

On Oct. 22, it will make a presentation to the Portola Valley Town Council about ways license plate readers could be used there and the efforts that would be taken to safeguard the vehicle information collected.

Town Manager Nick Pegueros said questions about data security raised by town council members after an automated license-plate reader was deployed earlier this year resurfaced when the Sheriff’s Office asked to use the surveillance equipment again this summer.

The discussion next week is just “an information session,” Pegueros emphasized.

Email Bonnie Eslinger at beslinger@dailynewsgroup.com; follow her attwitter.com/bonnieeslinger.