This happened in PvE situations too -- Everquest always had people, especially guilds, running ShowEQ/MacroEQ to read mob locations off of the wire/from memory. Often could be used in non-unethical ways[1]

Sometimes you got funny situations like top guilds cheesing new raid content in their race to finish it first, leading the devs to go "cmon bro, you only played yourself" and then patching it immediately after, but almost never taking any loot away or banning anyone.

Also funny is the common situation where you don't want to _admit_ to everyone in your guild that you have at least one person running it, but you can kind of figure it out and it becomes an open secret.

1 - These are the days where you might have to clear down a dungeon 4 hours to see if a mob is up, or, even worse, to see if it's camped or not. Alternatively (or as a cover) people just parked alts but you get the idea. Also, come to think of it, Diablo had this too with maphacks and grabit and such