My WordPress blog has been getting hit hard by spam lately. I've had some rudimentary tools in place (moderating comments with more than two links in them), but even that has become tiresome. It also hasn't solved the problem with trackback spam. Every day I've been getting at leat 10 comments or trackbacks to either moderate or delete.
WordPress has a system called Akismet that checks comments against a centralized spam database, but those services never work as well as intended, in my opinion. I just wanted something to nuke the spam on the spot while leaving legit comments and trackbacks in place.
For trackbacks, I chose the Trackback Validator Plugin, which, simply enough, checks to make sure the trackback actually links to your site. (Most trackback spam does not.)
For comments, I wanted some sort of "Captcha." A Captcha is one of those computer-generated warped images that requires the user to type in the text. I personally hate dealing with them as an end-user, but they are quite useful when it comes to spam.
Problem is, in order to run an image-based Captcha, your server needs to have certain programming libraries installed. So I looked for other options.
WordPress - Hashcash looked really interesting - it uses JavaScript to validate the post, with no need for extra effort on the part of the end-user. Problem is, the plug-in choked when I installed it. Never mind.
I had the same install problem with WP-Gatekeeper - that was supposed to work by having the end-user answer an obvious question before posting the comment. Oh well.
Finally, I settled for Did You Pass Math? This handy little plug-in was a snap to install and requires your user to add two single digit numbers to pass spam muster. I did choose to modify how the input field showed up on my blog to make it more obvious that it was a required anti-spam measure, but that was as simple as adding a few words to the code. Even someone who doesn't program should be able to find out where they can do this, if so desired.
As a bonus, I'm also now filtering out dumb-ass people who can't add two and two together!
You can see what this plug-in looks like by checking out the comments section on my blog.
I'll post an update on the spam blocking in a few weeks. Cross your fingers!