[The Finman]

Because of some of the idiotic stunts some of it's members pulled because they thought they were anonymous. Many of these stunts resulted in retribution against it's members. AOL decided in order to try and protect it's members, it now routes their IPs through AOL corporate proxy servers.

But after many complaints (especially from Wikipedia) of about it's users, AOL is now supplying XFF header information to websites (such as Wikipedia) to help identify AOL vandals.

http://en.wikipedia.org/wiki/WP:AOLIP

What all is required for them to transmit the XFF header information to you isn't really clear. I guess you will need to submit your web logs to AOL if they are causing problems to your web site...but if my experience with AOL's abuse department is any sort of guide, I will wish you lot's of good luck in your endeavor.