I just went to the members page it most of them joined awhile ago and still haven't posted anything. If you join and don't post anything ever, will your account be deleted so someone else can choose that username, provided you haven't made any posts?
It would be a good idea if like someone hasn't posted in a week or two, the auto send them a message telling them that they should post something in case they forgot. They may have forgotten that they joined. If they still haven't posted ahything after like 5-6 months, there account should be deleted.
This is just a thought.