Usually if a server I'm GM'ing on allows me to have a legit, I just make sure I keep my identity secret. Not because I have anything to hide, but because I would rather not be a part of stupid drama over false accusations. Luckily for me, I don't PvP, nor do I participate in any WoE. xD
Although I have GM'ed on servers with small, close-knit communities, that were comfortable with me playing on a legit because they knew me well enough to know I wouldn't cheat.
I think the main targets are newly hired GM's, because most communities are very cautious of new GM's in the beginning. And some like to try and harass the GM's, too, as some sort of way to test them.