Every time you tick a box that says “I’m not a robot” or select all the pictures with traffic lights, you’re taking a tiny test called CAPTCHA — short for Completely Automated Public Turing test to ...

All: In a further effort to deter spam, Roanoke.com has added a "captcha" code bar for readers to type in before they enter a comment. We hope these human-readable images will thwart the loathsome ...