The image - known as a CAPTCHA - is designed to be unreadable by automated scripts which use pages like this to automate the sending of spam email through entirely innocent third party web sites, like this one.
How does it work?
A CAPTCHA image shows a random string which the user has to identify and type in order to submit a form. This is a simple problem for (seeing) humans, but a very difficult problem for computers (or automated scripts) which have to use character recognition, especially, because the displayed string is aligned in a way, which makes it very hard for a computer to decode.
Go back to the formThe CAPTCHA Project is a project of the School of Computer Science at Carnegie Mellon University.