OT: I highly doubt you'll be banned. This is essentially the same as getting people to flag themselves through aoeing. And that's allowed I believe even if not encouraged. Blizz's solution to that is implementing a system in WoD where you can't accidentally flag yourself.
This, while I wouldn't consider being a good sport, isn't that bad. It's not like they can endlessly gank you as after they are killed, they'll leave the realm. Its impossible to endlessly gank them. Yes, doing it to those on PvE realms who never have to deal with ganking isn't exactly the same thing, but its more of a mental thing than actual disruption of play as traditional ganking.