Over the past few weeks, something happened and my spam comment count went from about 100 per day to over 600 per day. I use multiple plugins to combat spam (Bad Behavior and Akismet), and they do a fabulous job catching the spam before it gets posted.
But they do occasionally catch the innocent commentator. This isn’t good. When the count was 100 per day, I could go through them and pull out the real comments. Now that it’s up to 600/day, I just don’t have time.
So I’ve implemented a “Captcha”. One of those goofy things that verifies you are a human before you can post a comment (here’s a cool paper from Carnegie Mellon on CAPTCHAs). I’ve seen some that use barely decipherable text images and they drive me nuts. So I went with a “math captcha”. (I’m looking for one that is similar but has provisions for the visually impaired ”” anyone know of one?) UPDATE: I found Pete’s Math Anti-Spam that has voice capability and have installed that.
In the current incarnation, it looks like this:
Just answer the simple math question and you’ll be good to go.
Sorry for the hassle, but it should help reduce the number of “false positives” from the spam catchers and let the real people comment freely.
I’ll try it for a few days and see if it helps (it already seems to be doing just that).
UPDATE: I found another math based captcha here. This is an example:
I think I’ll stick with the one currently in use. There was a time where I actually could have solved this. I made it (barely) through one semester Differential Equations in college, but I’ll be damned if I remember any of it…