Elise is collecting together tips about how to combat comment and trackback spam for Movable Type users. To continue the theme, I’m going to use this entry to list the ways in which I prevent spam from getting through.
- MT-Blacklist. Pretty much mandatory if you have a Movable Type weblog and have comments or trackbacks enabled. It doesn’t require much effort on the user’s part but is very effective.
- Renaming my mt-comments.cgi and mt-tb.cgi scripts. This was one of the first methods I tried back in October 2003 and is detailed here. This works reasonably well as it makes it harder for automated bots to guess the URLs of your scripts.
- Closing old comments. This does require a bit of effort every day, although Kasia offered a Perl script that can be run as a Cron job to automate the process. At the moment I’m using to close comments and trackbacks on entries more than 60 days old but I believe there may be better script out there. MT-Close2 for example looks interesting.
- Real Comment Throttle. This allows me to set a maximum number of comments to receive per hour or per day, to limit possible damage caused by a flood of comment spam.
- MT-DBSL, which forcibly moderates any comment coming from a known open proxy. Alas it doesn’t filter much but it does help.
This seems to keep the problem pretty much under control for me, though just because it works for me doesn’t mean it will work for you. Elise suggests a few other methods that you can try, however, including a hash generator that can further prevent automated submissions.
Some bloggers have implemented ‘captchas’, which show a number in an image that you then have to type in to be able to enter the comment. I think you can probably guess that I’m not keen on the idea due to accesibility reasons.
By the way, you may have noticed that I’m no longer forcibly moderating non-TypeKey comments. I will re-apply moderation if I’m going to be away for a few days or if the problem gets worse, but for now I’m letting any comment that doesn’t fail the automated checks through.