I am the FA on a few sites. I am constantly blocking proxy addresses to keep them out. I also watch the new users sections to see how many are registering from a single ip address, then if there are no posts for the users block them. Seems to work, so far no one has been blocked that had a legitimate need for access.
2007 Chevrolet 2500HD D/A Classic CC Log Bed 4X4
2008 Jayco 299RLS
W6DCS, ex KC6LKS