I was probably dealt the worst possible hand, where our gladiator thought his role was to "just kill stuff", though our healer wasn't bad, so I guess it could have been worse. Everyone but myself were PS3 players, so they weren't very talkative or responsive when it came to strategy. At some point through the dungeon, after the PUG and I (ARC) were tired of having to tank to get mobs off the healer, we let the tank go on his merry way and attack whatever he wanted without our help until he responded, as all previous attempts at communication had failed.

We weren't really mean about it, just making a point that he needed to stop and listen. When we finally got a hold of him, we pretty much explained the whole deal, and taught him what his role was supposed to do, and gave him as many tips as possible to get him to tank better. He only kind of got the tanking multiple enemy thing down by the end, but we still pulled through. The majority of people who do dungeons are quite reasonable, even the ones that know very little about MMOs or the game. As for the ones that aren't, there isn't much you can do except for move on.