"I'd actually be interested to know how a jet engine would cope with a quadcopter going into it. Don't they test engines for resistance to consuming birds etc? Obviously a quadcopter is potentially a bit more solid than a bird but not substantially so in most cases."
US Airways Flight 1549 ended up in the Hudson river because it consumed a couple of birds... The engines are simply tested to ensure they don't explode into a shower of high velocity sharp bits, which would cut the fuselage into shreds. Birds will still total then engine. At takeoff, you need every bit of power you have, you've got your maximum fuel load, and you're trying to climb. Lose an engine and you're going down, hopefully you're lucky enough to have a nice fire-quenching river locally and a damn good pilot behind the stick.
A strike during landing isn't "quite" as bad, but at low altitude you could do without a sudden reduction in power because some idiot has flown an RC plane into your engine, and if you are forced to do a go-around, you're back to wanting all the power you can get again.
Only the other day we were hearing about fire fighters in the USA being prevented from doing helicopter water drops because there were drone sightseers buzzing about.
So I'm erring towards the "open season" solution. Airports are controlled airspace, you're not supposed to be there, end of! You shouldn't need to see written rules to realise flying a drone near "real" planes isn't a bright idea... So as they never manage to track the owner for punishment, maybe a blanket rule that you're allowed to bring down any drone trespassing into controlled airspace....
... and I'll go fetch the 12 bore.