Pulling towards you as you exit. Particularly with stalls: This means you're unhygienic hands are touching a handle that everyone else will have to touch (and has touched). With respect to the bathroom exit: Somehow grown men (and women? Don't use their bathroom so can't say for certain) haven't learned to wash their hands after using the toilet. At least I know who not to shake hands with in my office, and who isn't allowed to touch my workstation.