Author: S.Sblam (22 Oct 07 6:19am)
If you take a closer look at most active comment spammers, many of these IPs are just innocent ISPs proxies (which are not wide open and generally doing a good service).
My suggestion is to use whitelist of trusted proxies and only ban IPs reported by their X-Forwarded-For header.
Users of http:BL won't need proxy whitelist. They could just check any X-Forwarded-For header in addition to source IP.