I decided I missed the atmosphere and tension of a good Left 4 Dead campaign, so instead of ploughing through Alan Wake some more I booted up Vavle's classic co-op shooter.  When I stopped playing it a while ago, I forgot about how great the game is in so many ways.  I still need the Achievement for completing all campaigns on expert - so I decided to have a run through 'Death Toll' on expert - so far so good. 
 
Didn't take me long to get back into it - even seemed to have a reasonable group of players join me.  We got through the tunnel, and into the cabin easy enough, then we made it through the Sewers without any major issues, going down to last man standing when the tank attacked - but rescuing everyone after finishing off the tank.  Everyone sticking together, covering each other and helping each other out.... So we get into the Kaboose, and start the trainyard and one of the team, xxConnoRocksxx or something, goes completely schizo and starts dicking about, running off on his own, shooting the team.... We vote him out - but he comes back - a with a griefing apprentice so we can't vote them out - and they just kept dicking about - killing everyone before we could leave and enter the trainyard.... 
 
Now this is incredibly irritating... I need to find a decent group of peeps to finish this achievement... And Valve need to think about the consequences of this grief on expert level.  Other levels - it's easy enough three people can get through with one idiot.  But massive friendly fire damage and high difficulty means it's impossible for a group to succeed on expert with one numpty.  They should code in some thing that works out when someone is being a dick and kicks them off the servers for 72 hours without allowing them log back in... And that might solve the - two griefers on one XBOX - you can't vote them off ! Grrr! 
 
Rant over....