These IP addresses are mostly going to be in use by new ISP accounts now, so I think a good idea would be to put the spammer's username, IP address and time of spam on each row instead of just scanning and attempting to exploit/DoS attack them (or whatever anyone plans to do with them). This way we prevent people doing anything to IP addresses that have long since been re-assigned, and we keep a record of which IP address was tied to which username at a certain time.
I strongly disagree with those that contact police over forum postings (the Internet isn't for anyone to regulate and free speech should remain), but if the spam was pertaining to criminal activities (e.g. ****** card fraud), the forum would then have a record of the perpetrators' actions and IP address.
