A good PvP server would have limitations in place and not go for the "anything goes" bs. The only reason Bliz says it's ok is because it would be too much work for them otherwise.
Either way, doesn't change my original statement that the people that do it probably have some kind of issues. And I'm talking about the type of ganking that shows no kind of sportsmanship, where 3 people will run over to kill you if you're in their line of sight, not just someone that attacks occasionally.