You say you have his Address, Teenager or not I have found real world physical baseball bats and the guy's are a good hacker deterrent. OK OK overkill I know, but you see as he disclosed E-mail information why not disclose his it address as it is static, I can make it so as if he is a teen using his mums computer, that he looks like the filthiest pervert on the planet. Or escalating a little, I can make sure that IP address never successfully receives another packet from the net, making his only option to request an IP change. Well the offer is made.
