Personally, I wouldn't ban him. He clearly loves this board, evidenced by the 5000 user names he's created this month. And it might be one of the only things in his life that brings him joy. What if he went off the rails without this board? I say let him have his fun and encourage him to be better. Crash has every opportunity to be a little better today than he was yesterday. We all have choices to make. Blessed are those that make the heroic ones.
PS. I've never been banned from a board. I'm not sure I've got it in me to even know how to even go about it.