Hey everyone, I wrote a guide for configuring mod_security to block referer spam. (Referer spam are those HTTP requests you get on your webserver with faked referer fields that point to some spammer's website and pollute your logs.)
Most guides online show you how to block requests by blocking HTTP requests based on keywords in the referer (e.g. poker, viagra, mortgage). I take it one step further by showing you how mod_security can dynamically block IP addresses once they send enough spammy requests.
You can find it at http://linux.icydog.net/apache/refspam.php
(It is ok to post links like this in the forum right? I didn't find anything against it in the rules.)