CAPTCHA Protection
When creating a dynamic website, the developers need to take in to consideration abuse from spam.
Where the content of the website is subject to user submission, you run risk of getting abused by advertising, automatically submitted from spam bots, to promote their products and services.
To combat this potential problem an additional layer of security can be added to detect whether the client is human or a computer. This method is called CAPTCHA which is short for “Completely Automated Public Turing test to tell Computers and Humans Apart” [source: Wikipedia - 7 January 2007].
This approach usually involves supplying the user with an image, which they are asked to identify by typing a response to the image (e.g. supplying text as an image for the user to duplicate into an input box below).
There are a range of open-source scripts that work with PHP, that allows developers to integrate CAPTCHA into their script. The script that I have chosen to work with is called freeCap this provides users an image which they are asked to replicate into a box below.