My feeling is that we should delete his comments. If it continues, institute a ban on his user account, then if it progresses from their, his IP address.
I don't think it's best to fight fire with fire in this case by spamming him, as it will only possibly inspire him to spam more.
Social network spam is going to become more and more of a problem as SEO/scammers/spammers/crooks start figuring it out. Any ideas of how to prevent this from happening in the future? I know I'm annoyed when I get a social network spam email.
What about you, carlo2007? What do you think? Wait, I know: "HELLO MY DEAR My name carlo Siako, i am 25 years old . I saw your profile today...."