Logging IP addresses of visitors is a real simple thing to do on any web site, usually done without the person knowing it's done. The page you came from, operating system, browser version, monitor resolution, all grabbed in a fraction of a second with a bit of script that is free with most of the free counters. I just assume everybody is doing it, though I don't really know what for.

My firewall (zonelabs, free for individual use, anybody running Cable or ADSL should take a look at it, www.zonelabs.com) records hundreds of IP addresses of people who try to get into my computer every day, but I have no use for the data other then to wonder why they are trying. Every now and then I'll look a few up to see who they are registered to when I'm really bored, but changing your IP address is as easy as disconnecting and connecting to the internet again in most cases, so I don't really see why people get so upset by it.