I played another F2P MMO for 5+ years, (which I will not reference here so this post doesn’t get bombarded with spam reports like last time) and the devs had two types of accounts public and private.
Public, with their current forum name and a gold color, was usually low level for helping out when the chat mods were on vacation or a new game play had been added (like alliance wars in Empires).
Private with a secret name to keep an ear out in alliance chat (both mercing and alliance elder) for exploits, problems, and needed improvements.
Found out last year the head of the game company had a private account in my alliance (aka guild) for all 5+ years (they knew me from their previous game an arcade style RPG on the iPhone that I wrote several walk through guides about).
So yes if you are wondering, any alliance fellow, or merc, could be a company spy. Though they are not usually the heavy player and they usually stay out of the top alliances that ban mercing (too much work to meet the minimum play requirements).