Is there any way I can make it so that a users computer itself is banned, proxy or not? I have this user who if I ban, will simply go on a proxy and use that to spam my forum even worse than when he's on his main account, but his main account is so bad that I want to give him a permaban.

Is there any way I can ban a user from my forum based on his computer, possibly similar to how Microsoft bans entire Xbox 360 console, regardless the gamertag, from accessing xbox live if they are banned?

I know there are things like anti-proxy plugins, but I don't want to limit users from other countries who are using proxies in order to view my site on a regular basis.

Any help?