Just from the patterns I see, I strongly suspect our site url is sold or otherwise traded to people who make money by link seeding (putting site urls into forums to increase searchability by e.g. google).Is it the same person or they just keep making new accounts. Do Ftb ip ban?
I'm not the man to talk to sorry. But I can tell you that IP banning is always tricky. A single IP is usually meaningless (most users have non-static IPs to begin with) and banning a range has the risk of sweeping up legitimate users.