Unmanned aerial vehicles, known as UAV's or drones, are commonly associated with the military, but commercial drones are already here and are quickly becoming a hot commodity. This week's Consumer Electronics Show in Las Vegas features some small models that have hobbyists, photographers and journalist very excited, not to mention law enforcement. The FAA has selected six sites around the US for testing civilian versions of drones, with the goal of integrating them into national airspace by 2015. They could be used for search and rescue missions or monitoring pipelines for leaks. While no one disputes the FAA's regulatory role, some legal experts question whether it has authority over private drones that operate below 400 feet, and privacy advocates worry they could also be used for surveillance.