Perhaps consider this:
- Why would he want to do that? Probably you did mess up along the path too, pretty much...
- How could he get access to the website so easily? Either he's a good hacker and your security was poor, or you simply were very careless with the security ( I guess the latter is the case)
- Why would 70% of your members be so dumb to follow the words of an "outcast" and why would you - as leader - be unable to correct that easily? I mean, there has to be some sort of communication for your clan (Forum, IM, Email, whatever) that would have quickly informed everyone about the situation...