I'm not allowed to. They clarified that they were joking and that they wouldn't harass anyone if I told them to stop so unless someone says a comment is bothering them or that they were offended with something a crusader said I won't stop them. I let them crusade. That way we don't have a massive conflict.
Technically, four-wheeler is more accurate, but ATV is more specific
Unless you're talking about a NASA/ESA ATV Automated Transfer Vehicle, in which case four-wheeler is far more accurate.