Hmm... sometimes that kind of smiley would be good, but it could risk turning into one of those "inflammatory smileys" - the kind people use when they want to be awful to one another without actually posting flame. The :rolleyes2 smiley ( :rolleyes2 ) is an example of one we've already got which has that kind of effect. It tends to get used frequently as the "omg u r dum" smiley, and that's what could easily happen to a head-bangin' smiley.