After silvester I had a massive SPAM problem in the comments on this blog with more than thousand comments in one week. This forced me to deactivate the comment functionality and to make all comments since silvester invisible. Checking each comments if it was SPAM would have been to time-consuming.
Now I reactivated the comment function, but it’s now required to solve a simple mathematic equation as a CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart). I really don’t like CAPTCHAs so I didn’t added them from the beginning of this blog. But the huge amount of SPAM now forced me to add them. If you experience any problems or have suggestions for improvements please leave a comment or send me an email.
EDIT: I now switched to the reCAPTCHA service after seeing that my CAPTCHA code was too easy to solve and spaming was continued.

