If Mt Gox has a single deposit wallet for example, we could easily audit how many coins it has. We couldn't enforce rules, but if some people decided to set up

If Mt Gox has a single deposit wallet for example, we could easily audit how many coins it has. We couldn't enforce rules, but if some people decided to set up a sort of "best practices" website saying it's "SAFE compliant or something (Sure Against Forged Equalities), in which case beginners guide would be "ALWAYS GO FOR SAFE COMPLIANT EXCHANGES!" We couldn't punish them but it would allow some sort of feeling of safety(if minimal).