Ban open proxies

Tired of spammers

[madmatt69]

I figure there's no real reason for a legitimate user to use my site through an open proxy.

Is there something like a safe-list of IP's of known proxies that should be banned?

[madmatt69]

I've seen a few hacks for wordpress that use these lists, but I'm looking for a list I can throw into my .htaccess or .conf file.