vandalize their car.
Many years ago, the westboro baptist assholes tried to protest a funeral in McAlester, OK. Someone slashed the tires on the van they had driven to town, and nobody in town would replace their tires, until they went to walmart where a spineless manager made the techs change their tires. It was amazing, nobody ever got in trouble, and they never came back to that town. If you want a subset of assholes to stay away, sinilar steps should be taken to make thier visit expensive and difficult.