Some related posts from Technorati and Google.
[viveksharma.com: writings] Spammer hunting for fun and profit: Again, the important information is the domain part, which is spammerdoofus.com and the sub-domain, which is the “lame” part.Cross linked content: These are references to images or other files that are not actually part of the email, but when the email is opened in a client, the client will follow these links and display the appropriate files.
[ Geof F. Morris’s Indiana Jones School of Management] A Spammer’s a Spammer: I’ve noticed that, over the last couple of weeks, I’ve caught comment spam outbreaks before they start by watching the same spammers try to hit my referral logs. I use Referrer Karma to keep my referral logs from becoming spam pits, which saves me from having to remove things manually.
[Gay Orbitâ™] Comment Moderation: And only because I wish I had thought of it!! Dear Bishop, my girlfriend and I have an honest, loving relationship and have both agreed we want to wait until marriage to “do it.” We like to go on long walks holding hands and kissing sometimes.
[Unknowngenius.com] Dr Dave » Referrer Karma: anti-comment-spam plugin Spam Karma to block spambots before they even reach your comment page (note that you do not need to be running either SK or WP in order to use RK: this feature is entirely optional).
[Coldforged.org] coldforged.org » Blog Archive » Killing Referral Spam: on their pages, so any referrer spammers will get links and corresponding Google Juice.* Many sites have public links to their referral pages which can be spidered.* Site stats can be bloated by referral spammers so that getting an accurate record of your readership is all but impossible (hat-tip to Rudy).* Obviously the more referral spam hits you get the more bandwidth that gets used. For those on limited hosting plans or for hosts themselves, this can be costly and burdensome (hat-tip to glo).* Some blogs have scripts to pick up the most common referral addresses and link back to them (hat-tip to Shadow).
Reflected tags on Technorati: Blog, Referral Spam, Targeting Spam