A client wanted me to implement a drop down contact form that was triggered when the cursor hovered over a button in the site’s navigation. This was no problem, and I delivered some code using script.aculo.us‘s blind effect. A few hours later, the client contacted me and said that as he moved his cursor around [...]
Defeating contact form spam by hiding the webmail script
How to defeat contact form spam bots through the use of a challenge-response system.