Oh, yes, the people behind it are incredibly irresponsible. And stupid in certain regards. And need stringing up/shot/culled/etc
But it would be reasonably easy to evade the authorities, especially as the authorities (clearly) are too stupid to do anything about it. But, in their defence, they are civil servants. Even me - the stupid kid from the local comprehensive - could run rings round them for ages, and keep the airport closed. The only effective counter measure is to bring each device down, but I could just send up another, and another, and another, and so on.
I doubt its a foreign power behind it. Because you'd hit multiple airports, particularly Heathrow. So that leaves a Swampy type tree hugger, or somebody who plans on 15 mins of fame using a fake social media account. I'm leaning towards the latter, but who knows, and I suspect we will never find who.