Is using NMAP to find out about someone illegal? Ok, here is the background story.
For the past two days, somebody from the same address has been scanning me CONSTANTLY. My firewall has stopped it and recorded it, but it is really getting annoying.

Well, my good friend in real life (known has hobbdebub on here) came over. He came over to get some code and stuff...anyways, I told him about it, and he was like, "Scan him back. Maybe it'll stop him." So, I download nmap and scan him ( he is wide open to the world and running windows, maybe a script kiddie with a new toy), but the first time actually gave me a blue screen (yes, a bluescreen in Windows XP, needless to say we both had a large laugh.) So I do it a 2nd time (without any other programs open and my firewall down) and it worked and it gave me the info. Well, that was all fine and dandy (he hasn't scanned me anymore, and that was 30 minutes ago), but I wasn't satisfied. So I went to samspade.org and did a whois on his addy. I got the admin's e-mail and sent an e-mail to ask if they could do something.

Anyways, my question is, is NMAP illegal to use, and did I do the right things so far? Cuz I have had suggestions to nuke him, but I don't want to stoop so low as a script kiddie. So, am I doing right by sending e-mails to the admins and letting them sort it out? Thanks.