People say that there's usually about a 10 year lag before tech from the military enters civilian use. Since drones showed up roughly 2003, it stands to reason that 2013 is when we should first starting seeing the tech become civilian viable. In fact that seems to be true, there's a whole lot of DIY material out there, and that's from people who don't have real world experience. I wouldn't be surprised if as military…
They're born out of the hobbyist RC scene and were enabled by Chinese investment in cheap RC parts development.