So, this happened on Ragnarok. I just joined an Amdapoor Keep (in progress) with the only human member being a freaked out tank (DRK) (shortly after a SCH and a RDM join as well).

So what the tank claims: his party members were 2 BLMs and a WHM with names just like gold sellers you see in the big cities. They teleported around, AOEd some mobs and then left the dungeon. The dungeon was 3-4 minutes in progress as I joined, the first 2 mobs were alive (a cultist and a demon) as well as 1 Dullahan along the path. The rest of the dungeon before the 1st boss was literally "cleared". Furthermore, after we've beaten the 1st boss, the 2nd floor was nigh empty aside from 2 gargoyles.

My friends, the gold-farmer bots (or whatever the hell they do) have evolved up to the point of joining dungeons and doing gods-know-what there. This is more than just annoying shouts about selling gold, this about literally disrupting the game-play. Be warned, be alarmed, and let SE know so they do something about it!