How CAPTCHA evolved from typing distorted text to analyzing behavior, context, and risk When most people hear CAPTCHA, they imagine a small checkbox: ☐ I’m not a robot Or perhaps a challenge asking them to select traffic lights, bicycles, buses, or crosswalks. But modern reCAPTCHA is much more interesting than that. In many cases, you don't actually solve anything. You simply open a webpage, move your mouse, click a button, fill out a form—and somewhere in the background, a...