[WebCarnage] very nice post, not a lot of people know about that method.

A while ago I found some kid on Mirc boasting about amount of IP's he had collected. *Hint Hint* IRC hehe.

Now in most cases, there isn't much one can do with just the IP Addresses. Unless he or she wishes to scan those IP's but it is ILLEGAL. Also, a good configured system, such as all patches r in and firewall configured properly...in most cases can't even scan a system like that if it is in stealth mode. Also blocking ports such 139 and similar ports like that will diminish "attackers" any chances at collecting info about you.