Just a thought, brought about by this:
post #333361
If we add the flagging history at the top of the page where you flag an image, in addition to the "valid/invalid flagging reasons" section, it may prevent some of the re-flagging for the same bad reason.
I doubt it will get rid of it completely, idiots will always exist.
But hopefully some of the more intelligent flaggers that thought it was actually a valid reason will be stopped before a ban is needed.
Updated by Conker