When people mimic/say what you say in an annoying voice and say it louder then you do while you're talking or in an argument. Not sure why, but it is ONE of the things that just drives me murder rampage crazy. Just had some guy do it to me/another person in CSS when we made one mistake. I HONESTLY can't see how someone past 12 should be doing this, it is so fucking childish.
Hell, this was the reason I stopped hanging with a friend, because he would do it constantly whenever we got into an argument.
Also I messed with my in game resolution in CSS and it crashed. Now whenever I get into the start screen for CSS my screens color is all messed up and I can't seem to move my mouse, halp.