I've heard people say that you should not shield block when you are door blocking to keep an enemy from getting to the target that they are actually trying to attack. This usually involves letting one person get aggro against a monster that has no ranged attacks while a few other people use their bodies to keep the monster from getting within melee range of the target. This works well against Maruts, against the Kobold lietuenant in the Shroud and against a few other specific enemies throughout the game.
I understand telling people to stop shield bashing because you don't want them to generate aggro, but does shield blocking actually do anything to attract a mob's attention? Is there more to this than a"diplomacy on the chest" type of urban legend?