The rules clearly states that it's totally allowed to be an asshole but they are pretty fussy about these things.
A Game Master need to help and clarify.
C. Gameplay
Nostalrius Begins recognizes all valid play styles to be part of the game, and not harassment, so player-killing the enemies of your race and/or faction, including camping the spirit healer, corpses and/or gravestones, is considered a part of the game. While playing on a Player vs. Player server, you should always remember to protect yourself in zones where the members of a hostile faction can attack you. The act of "stream sniping" is not a violation of this agreement as we cannot intervene if someone in-game makes the decision to communicate their every move, thereby informing other users of their position and/or in-game status. Nonetheless, certain behaviour goes beyond what is considered fair and are considered a violation of this agreement. This behaviour includes, but are not limited to, the following:
Using or exploiting errors in design, features, and/or bugs to gain access that is otherwise not available, to facilitate and/or grant you an advantage over other players.
Engaging in combat whilst standing on a section of the world that neutralizes the ability of town guards to detect and/or engage you.
Engaging players through various world terrain, such as roofs that is otherwise not possible, to facilitate and/or grant you an advantage.
Intentionally not participating or otherwise being AFK within a battleground.