We all know of the ubiquitous CAPTCHA; those horrendous looking images that are designed to keep robots from submitting forms with spam in them because it is assumed that the robots cannot read the messed up images. The problem is, of course, that humans can’t read them either. We’re just better at guessing what the letters are. CAPTCHA, if you’re wondering, stands for “Completely Automated Public Turing test to tell Computers and Humans Apart.” A Turing Test is a test where a computer is able to sufficiently mimic a human to the point where another human cannot tell the difference between the two. CAPTCHA is the exact opposite. Its purpose is specifically to determine who is a machine and who is a human when user generated content is placed on a web site.