[kronusaturn]

I doubt terrorist-made drones will be remote controlled for exactly the reasons you just described; the skill level required is just too high. I'd expect them to work more like cruise missiles, a hand grenade strapped to a fixed-wing plane with a crude GPS-based autopilot that simply flies straight at the target. They might miss their targets more often than not, but that's not a big problem if your primary goal is to cause terror and mayhem.