[middo]

The biggest problem with having people's IPs, is that, if you're a malicious person, can check to see if there is a trojan on your computer, and then abuse it. It's not a matter of infecting you with a trojan, a lot of times people are infected, but either the (depending on the version) trojan can't broadcast itself, or simply is broken in some way. But if they know your IP, they can target you directly and try to access you through what may already be on your computer, get your passwords, etc.

It's a bad idea.