You could potentially flood the relevant frequencies with noise, but that's going to mean fly-aways and them dropping out of the sky in an uncontrolled manner. It's also going to play havoc with other things that use those frequency bands, some of which might have safety implications. OK if you don't care about the collateral damage - e.g. a warzone - not, really suitable for an urban area.
As others have said, I hope these idiots get caught and fined/jailed to the maximum extent of the law, but I suspect the damage is done. We can almost certainly expect legislation with even more limitations on where we can and can't fly to be introduced next year, and some form of mandatory registration/tracking seems like just a matter of time.