Introduction
Unless you are extraordinarily lucky, users are going to misuse, or worse, abuse your form. Typical misuse is entering the wrong kind of data, or leaving important fields blank. Typical abuse is submitting spam, or input designed to damage or take over your site.
In this chapter, we'll look at a range of different techniques for protecting your site. Which ones you need to implement will depend on your site. A quiet, private site with a few well-behaved visitors might get away with none; a popular high-visibility or controversial site might need everything here and more besides that.
