Spammer accounts, how can I block them by IP?

I keep having the same guy create new accounts and setting up fake Groups using Buddypress Groups to sell his fake stuff and offensive adult things!
When I use the Anti Splog to Mark him as a Spammer it makes his profile unviewable but he just keeps starting new accounts!

So how can I when I mark him as a spammer stop his IP address or any users with that IP address from registering on my site again?