This threat is indeed disturbing; a thought has just struck me; while we aviation enthusiasts are rightly concerned about the unique & fragile nature of the full-size collection, this idiot's beef seems restricted to model flying.
I know modern R/C transmitters are a lot more handy, frequency wise, than earlier types, but I wonder if this berk might try, with a bit of experimentation with his own controller to interfere with a model in flight ?
Should be possible to spot such a character, probably not standing around but in a car tailgate / van etc...
In the wrong circumstances this might lead to a lot worse than a pranged model, which the idiot would presumably count as a 'result'.