Mark Wickens noticed the same thing that I did today, bogus referrers in his webserver log. Where I just blocked the hosts manually in my firewall rules, apparently he’s making some changes to his Apache config. (The entry has since been deleted; however, he let me know that the Apache changes were similar, just using the Order and Deny rules.)
Hunting for others who’ve seen this, I found a post from Rafe Colburn (via Daypop, which is actually working today) that says I’m not sure what the expected return on such spam is, or why they’d bother with it, but I am somewhat intrigued.
He also found this Kuro5hin entry from last year.
Mark has noticed spammers previously and dealt with them in his linkback scripts: There is some attempt made to screen out search engines, bogus referrers, or referrers that no longer link to me for some reason. (The purpose of this is to track conversations and rewards links; people who link to me and then remove the link do not deserve to be rewarded. You know who you are.)
Finally, Stuart Langridge makes reference to the problem in passing, but his post is mostly about Pingback.
