Maybe you missed the part where there is a medieval style war going on between Horde and Alliance? Hitting defenseless targets is a valid tactic especially if such targets ultimately support the opposing side's war efforts (direct or indirect support in combat, contributing to the economy, etc). Yes, I will do everything in my power to "ruin" the gaming experience of the opposite faction since that is what I signed up for. No, I don't feel the urge to go on a rampage IRL when I'm not playing here. Do not dismiss the role-playing factor and do not equate this game to real life. Just about every player knows this is a game and treats it as such.
That being said, what the thread is about is something quite different. While stalking another player for hours is excessive, we don't need to make a rule against such behavior because it is so rare and in most cases, can be easily countered.