Over the last two months or so there has been a surge of comment spam on this very blog. It has come to the point where I have been erasing 200 email notifications for comments on GeoLand; all of them for Viagra and other exotic drugs.
The time has come to step up and do something about it. I wanted a solution that is easy to install and does the job right. Reading a few blog posts on other wordpress blogs that have had similar problems I decided to give Math Comment Spam a go. At a 4Kb download and 2 minute install instructions its not bad of a solution.
I just dropped the two php files of the zip file in a subfolder of my plugins directory (/wp-content/plugins/), enabled it, and dropped a small piece of code in my comments.php file and I was ready to go. Now spammers have to physically take a look at the form and solve a very elaborate math problem which might discourage them a bit, since now the whole process stops being automated (using automated spam bots).
While on the subject I have to note that while looking personally at all these comment notifications I might have missed a few good posts. If you don't see a legitimate post of yours left whithin the last two months, I apologize; please post again.
UPDATE (sep 16th): the math comment plugin does really work !!! I have actually received only one spam message in a period of more than a week, while in the past I had to go through hundreds of spam messages daily to see if there was any legit among them.