@ATC Watcher
What was interesting for us, ATC, was the lack of security of the control links. In fact one clever hacker in the USA and one in France have recently took control of some UAvs for brief periods to show how vulnerable the systems are and how easy it is to get "inside" the control systems.
What they actually did was spoof the GPS signals so the UAS had incorrect ideas of where it was. This only works for those UAS that navigate solely by GPS and have no direct control link. So the UAS is told where to go and flies there rather than being controlled directly by an operator in the ground segment. A UAS with a control link to a 'pilot' in the ground segment who has some level of telepresence such as a video feed or even just instruments would not have been vulnerable. So they cherry-picked their examples a little.
It does get worrying though when you think someone might play like that when a manned aircraft is flying an IMC GPS approach.