@Crum, et al
What I'm trying to say is that there's no difference, ethically, between 40 individual humans getting together and locking down a quest hub, which we would not say is griefing, and a multiboxer doing the same. The morality of the event (locking down a quest hub for the opposite faction) shouldn't be decided by how easy or hard it is, which is what your argument boils down to.

@Vecter
I think part of your point is valid: Does multiboxing 40 toons lag the server? I don't know the answer to that question definitively. I've been in Tanaan with my 15 against 60-70 on the other side and haven't noticed any lag. I wonder what the deciding factor is?