Since installing the blacklist I have had a noticeable drop in referral spam which is good news. The thing that does concern me is false positives. I have had to drop a number of keywords from the list because they are just too common: "hole" appears in "whole" which one search provider uses to tag the query with "wholeinternet"; "golf" was in the list but I since I am buying one there is no reason to block it.

The one keyword I am undecided about is "virgin". There are a high number of spammers still using the keyword but it means that every referral from virgin.net (there is a search engine there too) will get a 404. Koan too has changed her URL; can you guess why yakushitsu.blogspot.com gets blocked?

So, next time you get a 404 response back from a web site then check who referred you in the first place. They maybe stopping you from seeing the page so try pasting the URL into a new browser window. To the users of the virgin.net search engine - I am sorry but you will never see this post.