short of violence to enjoin and compel to follow it's own rules and not selectively enforce rules it sets for buyers and sellers. Isn't there some kind of contractual relationship here that is actionable? Certainly sellers have contractual rights that eBay treat them without discrimination and enforce its listing rules equitably. I think it can be reasonably argued that not enforcing listing rules (set by themselves) gives rule breakers a competitive advantage over those who follow the rules.