Most routers and/or modems nowadays as well as Windows XP Service Pack 2 have built-in firewalls, meaning even if someone had your IP address, they really couldn’t do anything. I cannot stress enough how unimportant it is for someone to have or know your IP address. Here, you want mine? 68.75.187.215. Really, it’s not something to fear. In addition, some DSL companies and all Dialup users will get a different IP address everytime they sign on (for DSL it usually rotates once every 1-3 days), so even if someone had your IP, it would be useless in a short amount of time.