I'm wondering if some terrorists could use drones around Westminster, landing on the roofs of various government buildings and causing havoc.
I suppose explosives could be attached and detonated from afar.
Any public building could be attacked in this way.
One surely can't have objects being flown anywhere at all by any evil-minded agent.
I've also read that one can have a drone already programmed, with no need to guide it remotely. A flying bomb in effect.