I follow the mechanics that I need to, but I tend to slack off on a few bosses. If it's just mainly a tank and spank (Sha of Fear, Empress, etc), I'll often tab out and switch background songs or use that time to respond to a text or something. --- http://breadfish.de/ http://thebest404pageever.com = best website ever.
Every time I decide to slack off(afk, snack break, etc etc) the raid tends to go downhill.
I'm so good I actually single affect 25 mans.
I think a more reasonable reason is that they see you slacking, think your'e cool, and think "maybe if I slack, I can be that cool too" --- If you believe in Jesus Christ , have accepted him as your lord and savior, and are 100% proud of it, put this in your sig