Regular readers of Mattsapundit will notice that this blog is devoid of comment spam. No Viagra from Canada, no midget porn, no 1% mortgages, none of that crap.
But scroll all the way down to the bottom of the page, and you’ll see that I’ve had more than 1,300 attempted spam attacks, all of them rebuffed without incident. This is because I use Spam Karma 2, an excellent anti-spam program.
The way it works is this: as comments come in, they’re automatically put through a series of filters, each of which can be configured for strictness. Each filter looks for a specific trait common to automatically-generated comments. One looks for comments generated too rapidly, one checks comments against an IP blacklist of known spammers, another checks for an unusually high number of links, while yet another checks for comments on older posts. There are 10 filters in total.
Each filter assigns the comment a karma value based on its performance. This value is cumulative as the comment makes its way through the chain. Suspicious comments tend to have more than one spam-like attribute, so the negative karma builds up. At a certain point, determined by a very high negative karma value, the comment is obviously spam and it’s automagically discarded. Buh-bye, scumbags.
Conversely, real, human-generated comments get good karma. They might have one or two suspicious attributes (originating from a browser that doesn’t support JavaScript, for instance), but they’ll pass the other filters and get posted without a hitch.
The software works almost perfectly. No spam gets through. I haven’t had a single spam comment since I’ve been using Spam Karma 2. That’s pretty impressive, considering I’m just using the default settings. Even better, it’s given no false positives to date. Every once in a while, the software isn’t quite sure whether a comment is spam, and it holds it in moderation for me to approve or deny manually, but that’s only happened maybe three times.
All in all, it’s a nearly perfect anti-spam measure. If you use WordPress, check it out.
