Special event: All hallow's eve

 All hallow's eve is over and I've yet to get a mount.  I ran SM Graveyard every day too!
Once a day no matter how busy i was I'd log on to WOW get a group going.  Now mind you I took some precautions and made sure people had the summons as there were some people who made things difficult.

Problems:

• They would get a group going get everyone else to summon and then when it came to thier turn they'd hearth out
•  Masterloot the instance and not tell people about it or do it last min.
• Boot the person who just used thier summon without giving them a chance to loot
  
• Leave group after everyone's summoned and get a new group

Solution:

•  Be Leader - form the group because at the very least you cannot be removed by the group
  
• Ask if that person has summoned the boss today yet:  I'd whisper everyone in my /who list with a, "Hi might I ask have you summoned the Headless Horseman today yet?" If the answer was yes then i'd not reply or reply with thx.  If answer was no I'd ask if they would like to join me.
•  Ask people of big guilds
• Ask friendlist first and of course your RL friends.

People who are in high end raiding guilds are less likely to do these kinds of things because they have a reputation to keep and they'd be Gkicked should thier guild hear about it in trade or complaints.  They are tarnishing thier guild's reputation for behaving badly outside of raid. I personally know of one hardcore raider a warlock that got gkicked because he was mouthing off in gchat and the officers felt that he was ruinining the guild's reputation