Pittsburgh police on Thursday used an audio cannon manufactured by American Technology Corporation (ATCO), a San Diego-based company, to disperse protesters outside the G-20 Summit -- the first time its LRAD series device has been used on civilians in the U.S.

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"The police fired a sound cannon that emitted shrill beeps, causing demonstrators to cover their ears and back up," The New York Times reported. For years, similar "non-lethal" products designed by ATC have been used at sea by cruise ships to ward off pirates.

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Now that the law enforcement authorites have begun using the LRAD in U.S. cities, a whole new marketplace for the company may have opened up. Don't be surprised to see a LRAD at an event with large crowds in your town sometime in the future.

Putnam acknowledged the potential for physical harm. "If you stand right next to it for several minutes, you could have hearing damage," he said. "But it's your choice." He added that heavy-duty ear-phones can render the weapon less effective.

A nonlethal device best known for beating back pirates off the coast of Somalia was deployed by local police in San Diego at political gatherings, and even at a competition to build sand castles, according to a local publication.

“The [Long Range Acoustic Device] was stationed by San Diego County Sheriff deputies at a recent town hall forum hosted by Congresswoman Susan Davis (D-San Diego) in Spring Valley and at a subsequent town hall with Congressman Darrell Issa (R-San Diego),” East Country Magazine reported after reviewing official records. It was also parked at a local sand-building competition along the beach.

Though the Long Range Acoustic Device can be used for hailing, it has also been employed as a weapon, most prominently in 2005 by a cruise ship, which used it to ward off attacking pirates. In fact, the device, which was developed after the bombing of the USS Cole in 2000, is designed precisely for that sort of mission. It can permanently damage hearing, depending on how it’s used.

Deploying the Long Range Acoustic Device to local events has provided ammunition to critics of Police Sheriff Bill Gore, who was the agent-in-charge of the FBI’s infamous 1992 Ruby Ridge siege. In response to questions posed by East Country Magazine about use of the technology, Gore said that officers had the appropriate training and that the device’s use as a deterrent is just a “precaution in case you need it.”