In Brickstown by the entrance to the Talos Island Safeguard Mission there is often a unit of PPD stationed, and not too far away there is a group of Not Automatically Confrontational (Yellow instead of Red) Crey. When I activate powers, such as CJ, while using Stealth by this group of PPD, the Crey and PPD begin attacking each other. Seems like it might be related. Bricks is so weird.
EDIT: I'm not sure if I even have to activate anything. Those mobs are just aggroing to each other from Really far away.