Worried that its citizens might be spied upon by eyes in the sky, a Twin Cities-area community has become one of the nation's first cities to stand up against drones.

St. Bonifacius, population 2,300, which covers a mere square mile, recently banned the use of aerial drones in its airspace, largely because of concerns about citizen privacy.

No drones have appeared over the Hennepin County city, St. Bonifacius Mayor Rick Weible said, but that day may come.

"There seems to be a rush to use this new tool within the U.S., but our state and county laws are fairly silent on the issue right now," he said.

A few weeks back, he and four City Council members got to talking about drones, and all shared concerns about privacy of those who might unwittingly be caught on camera. Their fears, he said, were not unlike those expressed during recent debates in Minnesota and elsewhere about using unmanned cameras to photograph vehicles running red lights and ticketing their owners.

So they voted to ban drones from city airspace up to 400 feet; higher altitudes are managed by federal authorities. They made exceptions for emergencies and search warrants, and for individuals flying drones over their own property. Violation of the ordinance is a misdemeanor.

The city also called for a two-year statewide moratorium on drones until the public can weigh in on how the technology will be used, and whether its images and other data can be used as evidence in court.

"Police have policies and procedures on all of the actions that officers take with firearms," Weible said. "I want to be sure that we're holding drones to that same level."

Unlike large military drones outfitted with weapons and high-altitude cameras, ordinary drones are remote-controlled flying vehicles that can be the size of a basketball and cost $25,000 or less.

Civilian use of drones is on the upswing: The Federal Aviation Administration currently allows about 325 police departments, universities and government agencies to use them to catch crooks, patrol borders, search for missing children and study crops.

Realtors in the Los Angeles area started using aerial photos and videos of high-value properties in 2011, but their drones drifted too close to fly zones for police helicopters and were restricted.

Even journalists are looking at using drones; the University of Missouri is offering a journalism class this semester on how to fly them because of their potential to gather images of breaking news such as floods and fires.

Unwanted eyes in the sky?

The American Civil Liberties Union has raised concerns about government use of drone aircraft, citing the Fourth Amendment's protection from unreasonable search and seizure. In early February, Charlottesville, Va., passed an anti-drone ordinance, apparently the first U.S. city to do so. St. Bonifacius adopted its ordinance Feb. 20, and held a follow-up discussion this week.

A bill introduced three weeks ago in the Minnesota Legislature would prohibit the use of drones to gather evidence or information about a person except in high-risk terrorist situations or after obtaining a warrant. The bill, authored by state Sen. Sean Nienow, R-Cambridge, has not received a hearing.

Hennepin County Sheriff Rich Stanek said Friday that he expects the use of drones to grow exponentially over the next three to five years.

Most law enforcement agencies are closely monitoring technology advances and their costs, Stanek said, but he has no plans to purchase any drones or seek federal clearance to use them.

"This is great technology, but we've got a keen interest in protecting privacy and civil rights for our citizens," Stanek said. "The question is how we'll do this and balance it all out."

Tom Meersman • 612-673-7388