Simon Willison’s Weblog

Blacklisting Comment Spam

2nd September 2003

I’m fed up with comment spam. From now on, any comment I judge to be spam will be deleted, and the domains linked to from that comment will be blacklisted. Any future comments that contain links to those domains will be refused. My blacklist will be made available as a simple text file, one domain per line, at blacklist.txt. You are welcome to grab a copy of that file once every 24 hours and use it as part of your own comment spam prevention system. I will manually approve all domains that are added to it to ensure only domains of a dubious nature end up blacklisted.

If you start using a similar system, drop me a line and I will start using your blacklist as well (note that I will not merge it with my own public list). If I find you have been blacklisting innocent domains I will cancel my subscription to your blacklist. In this way, I hope to build a decentralised web of trust whereby other people’s recommendations help my system combat spam better.