This really isn't anything to worry about, just some attention-seeking youth caught up in the romance of the media-glorified "computer hacking wars" that will never happen. If he posed any significant threat to mmowned or affiliates, you wouldn't know an attack was taking place until it was too late. He's probably trying some stupid shit that a google search for "vBulletin® Version 3.6.8 exploits" would turn up (or milw0rm exploits, if he had ever done anything of the sort before).
DDoS is a pretty crude attack, IMO an XSS attack would've been his best bet (I haven't really checked the site for vulnerabilities, but most sites have them).
As for brute forcing, was he just trying to BF an admin account?
Kids these days -.-