Possibly a new hack?
Okay, so, I was going through the "In Search of the Book of Ancient" questline, and at one of the points that I had to go to Spiruna, when I exited her little building, just to the right there was a magician (Evan, I believe...it had a horizontal, directional mob attack) attacking the Lunar pixies. This wouldn't be so bad if not for the fact that the Pixies were moving purposefully towards him. Now, I'm well aware of the whole vaccing thing, but that's when they beeline it through everything and everything to the person, correct? The pixies were rather moving towards him, and as best I could tell, it was because he was auto-aggroing them. Pixies (Lunar, at least) cast a defense-up spell when they get aggro'd, and that's what was happening. An impossibly large portion of the map was spawning, casting defense up, and then making their way down the platforms to the magician. I don't know why he didn't auto-cc when I exited Spirunas building, but after I had left (I didn't stay too long, but long enough to be sure of all I've just said) and came back later, he was gone, and left his mark--a massive pile of loot in the bottom right corner. I had gotten his name though (unfortunately, I no longer remember it) and was tracking him, switching to his Channels, and best I could tell, he was also using auto-CC.
Summary : A (possibly) new hack that auto-aggros the monsters on most of, if not the entire map so they move of their own accord (Not vacced) towards the hacker, who is botting his attack, and auto-ccing. I apologize if I didn't explain this very well, but I did the best I could. :S