First, one user cannot inflate the Top 50 numbers. One user can only register one view on any one image. Second, if a thumbnail is a sub-image of the full size image, it is ok. If the thumbnail has nothing to do with the full size image, it is not ok. It's always possible for us to miss some that should be removed. If you notice an image that you think violates the rules, please let a moderator or admin know.