This is actually the best way to deal with organized bigotry. People have done things like this to the Westborough Baptists and it gets rid of them a lot sooner. Just put up a sign saying you'll donate $x to someone they hate for every half hour they're there and they take off a lot sooner.
It's like that X-Files episode where the only way to cure someone of a mind-controlling worm was to inject them with another worm so the two would kill each other like fighting fish.