I didn't want to put too much speculation in my comment, but you're right that there are a ton of things that individuals could do with drones.
Here's a movie plot attack: A week/month/etc beforehand, plant 4-8 drones a half-mile downrange of the airport a VIP is scheduled to fly out of. When their plane takes off, trigger the drones to fly into the the plane's turbines. A fully-loaded plane with no working engines would quickly stall and turn into a fireball on the ground. You might not even need explosive payloads for this to work.
Targeting something stationary at a ___location known well in advance would be even easier; like say, a podium at an outdoor speaking event. I wonder what speed an inverted drone, accelerating toward the ground, can get up to while controlling its impact ___location to within a foot. Might be that adding an explosive is largely superfluous in that situation too.
I don't think kamikaze drones are even remotely practical as weapons for assassination. You'll have big issues with accuracy, lethality, and the element of surprise. It could work, but I don't see any circumstances where a hunting rifle wouldn't be a far better tool in every aspect.
Drones are too slow to catch-up with a plane that's taking off. Not to mention the fact that those things are so fragile, the moment they get near a jet engine they will disintegrate.
The plane's future position can be accurately estimated as soon as it spools-up on the runway. So the drones wouldn't need to catch up, just fly up to intercept. To ensure turbine destruction, the drones could have a payload of ceramic ball bearings, explosives, or both.
A passenger plane taking off is going to have a hard time seeing (let alone avoiding) such small, maneuverable craft.
Of course, this is a movie plot threat. Really, nobody is going to spend the time and resources to program drones like that.
People associate drones with multicopters. But really they're UAVs.. or.. you know, what you call drones, and can also be planes.
small/cheap (800USD) electric powered planes can go about the same speed as an airliner at take off, that is, 400km/h.
any faster and it needs to be turbine powered.
Also you'd go the opposite way (toward the plane) so the speed dont matter much...
Now, good luck to aim for the turbine - for all turbines, at once.
The drones you buy at RC shops, yes.
Do a YouTube search for jet powered RC planes and you'll find several that exceed the takeoff speed of a commercial airliner.
Jet engines have to survive the Chicken Test, which is to throw a frozen chicken into the engine running at full speed. A drone would have to be made pretty chewy to stop a jet engine.
And then the plane just lands. They can fly with an engine out.
"The most pyrotechnic test of all requires that dynamite charges be strapped to the compressor blades and detonated while the engine is going full blast."
Good point, but I think this hasn't happened because almost nobody is a psychopath, and most psychopaths are incompetent. If I believed otherwise, I wouldn't speculate about these things publicly.
Also, it would be hard to pilot multiple RC planes or helicopters simultaneously. Any attack that requires people cooperating is much less likely.
Psychopaths have a wide range of traits, but I believe those who would consider doing something like this, also tend to have poor impulse control that may interfere with their plans ahead. What makes it a terrifying possibility is that terrorists, who I don't think are all psychopathic, may have a better chance of pulling it off.
Not to mention that the vast majority of people who would be willing and capable of pulling off such an attack are probably people in government, so government regulation wouldn't make sense as a recommendation.
The same can be said about almost any terrorist action. They're not generally limited by what is possible to do, but mostly by what people are willing to do. That something like this hasn't happened just shows that there just aren't that many crazy people out there.
RC Planes are far cheaper than drones and can fly FPV and have been around much longer than drones. They can also carry very large payloads as well. These whole what-if scenarios are good to hypothesize, but assassinations happen if they want to happen. They are not going to happen more because of drones.
Here's a movie plot attack: A week/month/etc beforehand, plant 4-8 drones a half-mile downrange of the airport a VIP is scheduled to fly out of. When their plane takes off, trigger the drones to fly into the the plane's turbines. A fully-loaded plane with no working engines would quickly stall and turn into a fireball on the ground. You might not even need explosive payloads for this to work.