During the three months since I first installed WordPress, I have received HUNDREDS of WordPress Blog comment spam — spammers (and their evil automated programs) trying to promote all types of products and websites (even though the links have nofollow attribute set!)
While the comments never made it to the WordPress Blog web pages you see, they did get sent to me for moderation, and this was just too time-consuming (to find the one valid comment out of hundreds).
To find an automated (and not burdensome) solution to this problem I installed SI Captcha Anti-Spam for Blog Comments which you can find on this web page: http://wordpress.org/extend/plugins/si-captcha-for-wordpress/installation/
As the name implies, this is a Simple Captcha to defeat spammers. The definition of a Captcha is “A distorted image of letters and numbers used to prevent automated use of websites; Anything that a human must do to prove that they are not a computer”.
Captcha may sound like a silly word, but it has a serious acryonym: Completely Automated Public Turing test to tell Computers and Humans Apart. The Turing test is a test of a machine’s ability to demonstrate intelligence, and more information about this fascinating subject can be found on Wikipedia.
Our WordPress Comment Captcha looks like this:
A computer program can not (easily) “see” the letters inside the graphic, but a person can.
So, this is a simple and not too onerous way to separate serious commenters from spammers.
My steps to install SI Captcha Anti-Spam for Blog Comments was pretty straight-forward:
- Download the plug-in (either from within WordPress of via FTP) into the WordPress plugins directory
- In the WordPress Admin Options there is “SI Captcha Options” and there is a link which states: “Test if your PHP installation will support the CAPTCHA”
- I saw there that I needed to “yum install php-gd” to add the Graphics program GD to PHP, and then I had to restart the Apache web server (e.g. “/etc/init.d/httpd restart”).
- It was helpful to have a small PHP test program with these lines in it:
which allowed me to see that GD was now ENABLED (via use of the simple grep command “php phpinfo-test.php | grep GD”
It was very clear that my server was happy when I saw this very appropriate image for success: