As much as I generally disagree with every word that comes out of Bo's mouth, he's got a really valid point. If the guy wants to post here, and he's willing to behave himself, then leave him the hell alone. I'm not saying the mods shouldn't keep their eye on him, but people who come back to a site where they have been banned usually have one of two reasons:
1) They wanna be a jerk about it.
2) They realize that they got carried away, and want to make amends because they really do want to be part of the board.
Give the guy a break. Unless and until he does something wrong he's got just as much right to be around as any of the rest of us. People screw up, it's a fact of life…but if he really wanted to come in and cause trouble, he probably would have done it by now.