Simple rule; don't post anything you wouldn't say face to face.
Sorry, Lon, plenty of people been in trouble recently for using words face-to-face that the other person found "insulting".
AND VPNs or proxy servers ain't much help - most fora nowadays require an email address to send you a verification link when you sign up. You would need to find an untraceable email address (i.e. that requires no verification to sign up for) AND use a VPN/proxy every time you accessed that email address.
Cheers
UFO