Ha yeah. It is an expriment I'm wondering how long it will last before someone drops a XSRF or something. Will probably have to take it down within the hour.
I'm thinking about only letting users posts go through if their hash is lower than the previous users hash submission.
I'm not worried about you getting in trouble, I'm worried about those that visit your site.
Shut it down until you understand the basics of operating a site that 'anyone can edit', fix the problems and then re-launch. This is simply asking for misery, and not just yours.
Hopefully it is lega.