I'm getting "The change you wanted was rejected. Maybe you tried to change something you didn't have access to." for every IP address I try: my current Comcast address, and the addresses of a few servers I work on. I also put in 66.220.147.22 (www.facebook.com) just to see what it would do, and got the same message. I'm leaving the optional name and e-mail fields blank.
Tried it with an ISP email address, and a gmail address.