Unmanned drones have famously been used by the American military to conduct bombing runs of dubious legality in countries throughout the middle east, from Pakistan and Afghanistan to Yemen. However, American law enforcement agencies, already enjoying unprecedented use of techniques first mastered under combat conditions to control public protests, have long expressed an interest in deploying the technology domestically. If changes to American regulations currently under consideration by the FAA are ultimately enacted, they may get their wish.
The changes, due to be be proposed in January 2012, would allow for the limited use of unmanned drones over American airspace, paving the way for expansions to the exception in the future. What specific use is unknown, though it should be noted that non-military and non-law enforcement uses do exist. In Japan they're used by farmers as crop dusters, and drones have been employed in Russia to assist in examining hard-to-reach archaeological sites, both difficult to argue against. But though drone technology has numerous implications for American businesses ranging from agriculture to resource location, their main effect would almost certainly be the continued militarization civilian law enforcement.
Police departments in various jurisdictions have expressed interest in using the technology to track runaway criminals or search for drugs, and the LAPD has contemplated using them to replace or augment it's expensive helicopter fleet. However, officials in Florida, perhaps presaging how the technology will eventually be deployed, wants to use drones to patrol the sky around the 2012 Republican National Convention, almost certainly a sign that whatever other applications exist, first and foremost drones will be employed to manage dissent.
Dan Elwell, vice president of civil aviation at the Aerospace Industries Association, confidently states "It's going to happen. Now it's about figuring out how to safely assimilate the technology into national airspace." Safety concerns have been the biggest obstacle to allowing drones to be used over civilian airspace. The machines lack the "detect, sense and avoid" technology common in commercial aircraft, making midair collisions likely in high-traffic areas. Unfortunately for civil liberties defenders and privacy advocates, safety concerns may not be enough to stop the FAA from changing their rules. According to the LA Times, the FAA has already "issued 266 active testing permits for civilian drone applications".