Sounds like you weren't playing on a PVP server, I play on a PVP server and I am ruthless when it comes to rares/camping spots and such, especially since my realm leans heavily in population towards the opposite faction.
Fly down to check a rare and a pair of alliance are killing it? Gank them both then reap the spoils. Someone in your camping spot or farming your resources? Gank them until they leave. As long as you only proceed to gank them again if they choose to fight back again, like this 90 DK that kept on trying to get me back the other day, Blizzard sees it as world PVP instead of griefing.