Meta Comments on Comments

by Ed Rozmiarek

A couple months ago I upgraded our blog software to slow the number of spam comments that I had to deal with. The base MoveableType software was ok but the new "junk" system actually meant I had to handle more spam than the older "blacklist" system we were using. The blacklist filter would completely stop a lot of spam based on a list of banned words. The new junk system just marks spam comments as junk which must be examined. Also, it seemed like even more spam was getting through and was not being marked as junk.

After looking at the plugins for Movable Type, I found the Comment E-mail Filter plugin. This plugin uses a whitelist filter based on the e-mail address of the commenter. This system worked very well after I seeded the whitelist with the addresses of previous commenters. Those people who had previous posted comments would have their new comments posted right away while the spammers still went to the junk folder. In fact, after installing this plugin, no spam comments got through which meant I did not have to remove any spam from the blog.

However, I did have a couple problems with this system. Non spam comments from new commenters would still be marked as "junk" since they were not on the whitelist and there were a large number of spam comments to clean out every now and then. Since there might be good comments buried in the mass of spam, I would have to scan the spam comments looking for the valid ones. Luckily, I think I found them all and I don't think I deleted any good comments.

So, with some free time to tinker with the blog, I went looking for additional spam control help. I found a simple Comment Challenge plugin by the author of the old MT-Blacklist filter. This plugin uses a very simple CAPTCHA challenge with a hidden comment field. This is supposed to stop the spammers since they will not be sending the correct value for the hidden field.

Does it work? So far I would have to say yes. After installing this new challenge plugin we have had no spam comments make it to the "junk" folder and at least one good comment was posted to the blog. This small initial sample appears to be a very positive step. So, a thumbs up from me at this time.

If you have any trouble posting a comment to the blog, please e-mail me and let me know.

And yes, I know about the TypeKey system for commenter registration. I don't want to enable that system since I think that would discourage good comments.

Posted by Ed Rozmiarek at December 24, 2006 2:38 PM