#1 - don't play as the ingame name of artificialaiming.net in co-op mode. People get ROYALLY pissed at me and I've been votekicked out too many times to count. Especially when you "tag" all the baddies before the other 3 people even see them across the map.
#2 - the hack won't prevent a charger from knocking your ass off the bridge on the last map.
#3 - people are like "WTF" when I enter the sewers by myself...nothing to worry about here fellas!
#4 - people don't understand when I'm in the mall with them and I say..."Listen up you dumb son of a bitches...just grab the gasoline cans...I'll take care of the rest"
Same thing with no mercy finale stage on l4d1 :P.
Although I tend to lead my teammates astray and trigger traps on them. So it's more like "It's clear guis, I haz hax, gogogoggogo!" when there's a 3 hunter - smoker combo sitting just outside the exit.