In all seriousness, you need to remove your co-founder's ability to do anything on your site. If that's not practical, you should seriously think about making an exit yourself. For one, your business is now effectively dead in its primary market, it's going to be a long hard road back, if it's even remotely possible; for a second thing, you've just had your name and personal and professional reputation completely tarnished by what appear to be Michael's actions, and made worse by the childish retaliation on OPs profile (regardless of who did that).

The loss of your own reputation is going to be harder to come back from. Reputable VCs doing even basic due diligence are going to see this incident and aren't going to want to have anything to do with you, unless you show swift and decisive action, one way or another. So far your response has been neither swift nor decisive.

For what it's worth, asking Michael to contact OP seems like a really bad idea. He's hardly shown good customer services skills so far, do you really think he's going to do a better job suddenly?