"Drones transformed the battlefield in Iraq and Afghanistan. But their use has been extremely limited in U.S. skies. The Federal Aviation Administration essentially bans the commercial use of drones, and government use is still highly restricted."

"But that's changing."

"For a long time, drones, which are formally known as unmanned aerial vehicles, or UAVs, were exotic, expensive and out of reach for all but military users. Today, however, a clever hobbyist can have his own eye in the sky."

"That's the case for Andreas Oesterer and Mark Harrison. On a recent weekend, the two hobbyists are flying their collection of hi-tech toys over Cesar Chavez Park in Berkeley, Calif."