Yeah, that can sometimes be an issue. Of course, the staff is not always on-line, as those people have a life outside of IMGFlip too. Bullying people away from a site should indeed never be tolerated, and whenever I see that I always notify the site staff immediately. I guess I am a bit blessed with having a site mod as a "friend" (as far as you can speak of "friendship" over the internet) so my lines can be short, however even then it can sometimes take awhile.
People who try to bully others away is not something for a stream moderator to act upon if you ask me, but for the main staff. And these bullies are also the reason why a report list should never be public. Those bullies would abuse it and display the ones they want out for the whole world to see...