I'm always amazed people want it.
"Would you like to do a shitload of unpaid work and almost certainly incur a significant personal liability for any amount of defamatory content posted on the board?"
"Boy, would I?!"
Moderators would not incur personal liability, and broader questions of defamation/publication are still largely unclear.
that said, more editorial balance can’t be a bad thing. Go on, take one for the team