If I had a nickel for every unaware and ignorant tank I've had to deal with in LFG, I'd be rather rich right now. Been grinding levels on my WoW alts this month, and I've had tanks refuse to let me catch up, LoS me, and whine when I can't heal because I'm out of mana from blowing my cooldowns trying to keep them alive after zerg rushing into a room and pulling everything.

Today while playing my warlock I had a tank that beat all the previous tanks out of the water. The group had already used up all their kicks when I joined, so they couldn't kick him (apparently the tank wanted to kick others without realizing he was kick-worthy himself). He'd run off while we were still fighting mobs, and was playing Fury rather than Prot (the tanking spec). His excuse was that he was "topping DPS" and "was helping clear the dungeon faster", but it becomes an issue when he dies every other pull and nearly wipes the group.

Kind of sad when a warlock has to ensure a group has access to soulstone/healthstones and also tank with their voidwalker on top of DPSing when most old content is able to be steamrolled with little input these days.