Atomic Playboy has written a great little article on using Apache’s mod_security to block blog spam. Also worth a read is another article on reducing referrer spam using htaccess.
The Register has an interview with a professional blog spammer, if you fancy seeing someone failing to justify their actions.
Dave Child over at I Love Jack Daniels has written about his techniques for blocking referrer spam on his blog. He’s kindly posted some rewrite rules for blocking the most common spam crawlers. Assuming you’re running mod_rewrite, all you need to do is paste the lines into your .htaccess file and the scumbags should get [...]
To try and reduce the amount of comment spam that slips in here under the radar, I’ve launched a draconian, Blunkett-style crackdown by marking older entries closed to new comments. Of course comments will still be welcomed on recent posts.
Feed the Badger: 
(Entries) (Comments).
