We have been discussing the ability to return images directly from an action quite a bit. It wouldn't seem right if we had all these discussions and didn't quickly demonstrate how to implement a CAPTCHA system. CAPTCHA is defined as Completely Automated Public Turing test to tell Computers and Humans Apart. It is basically a simple challenge and response system to ensure that your system is not interacting with someone else's system when you are expected to be interacting with a human.
We are going to work off of the knowledge that we covered in the previous examples. No external requirements—just more code!