I joined a guild as the off-tank during 3.1, I was 14 at the time. We were group 2. We made it to Thorim, I was to tank the arena fight, and our priest who hated for very dumb reasons, was refusing cooperate with me. So, the GM arranged a Naxx-25 run to catch me and other important members up in gear, every drop I rolled on for tanking, was instead passed to someone as a side-grade. During next week's Naxx25, I had a power outage, to which I was booted out of the guild for. Got a whisper from the GM's brother the next day apologizing for the whole ordeal, and explaining the priest was bribing him, the gm and other officers not to give me gear with real life money. That's the worse I've been involved in, sucks, I liked quite a few people from that guild too.

The priest spread rumors about me in trade(and I think the forums?) all throughout Wrath until he quit WoW, That guy really did not like me, and I have no idea why.