Can one be neutral in disputed or non-neutral zones?

[jomar6960]

I have been zones like in ice crown specifically and in some occasions I have found some alliances that are completely blue, to what I mean is that it is supposed in these areas that are pvp you can attack the opposite faction, but I have seen some how many can not attack them, or are they "allies, friendly"?

If I go up to level 80 without killing someone from the opposite faction can this be achieved? Somebody explain to me please.

Unfortunately I have not taken pictures of this.

[GnomeChewer]

No, there is not pacifist PvE-only feature on this server.
What most likely happened was one of two things:
1.) They (or you) were standing in a Sanctuary zone (Dalaran, Argent Tournament Grounds, Shattrath, etc.) which is symbolized by blue lettering of the name above your minimap. Argent Tournament Grounds is a sanctuary in North-Eastern Icecrown.
2.) They were using a faction-swap hack which is very detectable and they will be banned soon.
The former is much more likely.