Usually these people will do it because they want out of the game and like to piss off anyone they can before they go. Many of those who come back after very long bans will just do it again. They only wanted to cause problems, they have repeated in the past and will do it again. As for shorter bans, I think they should just be allowed to expire. If people have learnt from the experience they will not re-offend. I am with many others in here. We are better to concentrate on attracting new players then trying to clean up the mess this would undoubtedly create. Afterall, cheaters, hackers, idiots etc can only drive the dedicated players away.