Like when you're chatting with someone online and they're all "oh i g2g (got to go) ill bbl (be back l8r (later))!!!1!1!one! *bangs hand against chest, insert 'Durrr' sound*"
It gives me the urge to shove their computer up their ass, whether it be a laptop or the whole damn system, tower, monitor, speakers and all. They're annoying.
...I'd have to break the monitor's screen first though, and smash the tower until it forms all sorts of lovely pointy and sharp edges...hm...