> If you click on NONE of the squares, it'll think you haven't visited any of them, since it won't have any way to double check the info. It's cleverer than th

> If you click on NONE of the squares, it'll think you haven't visited any of them, since it won't have any way to double check the info. It's cleverer than that. There are two positive controls (squares that are always black) and one negative control (always white). If you don't click both positive controls, or if you click the negative control, the page will tell you that you've failed the CAPTCHA.