A friend of mine has a website with a guestbook. Somebody has started flaming him big time - nothing threatening, just silly messages like "You're a moron" and "Nobody likes your music". But there are lots of messages, sometimes posted one right after the other. He can't figure out who it is or how to stop it, aside from removing the guestbook altogether. Is there any way to trace a flamer or is it just too much trouble to bother with?