thats how you ban a user from channel after the @ is the cloaked IP. everyone has different one. in order to find each users cloaked ip type /whois nick and from there you can get the cloacked ip.
[01:25] Eduardo is .@7DF8E9.9EAB25.7B9E8F.B643AE
[01:25] ••• Eduardo is «*»
[01:25] ••• Eduardo on irc.icq.com
[01:25] ••• Eduardo at (unknown); Edo is logged in as
[01:25] ••• Eduardo on #Channel, #Channel
/mode #channel +b *!*@7DF8E9.9EAB25.7B9E8F.B643AE