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The JS can't directly compute whether you have or haven't visited the link based on what it looks like. They actually used to (like 15+ years ago) but browser m
by lelandbatey 3y ago
The JS can't directly compute whether you have or haven't visited the link based on what it looks like. They actually used to (like 15+ years ago) but browser makers patched that REAL fast after some toy projects were able to reveal OUTRAGEOUS amounts of personal info just by getting someone to click a link.
Instead they have to have you the user do something to indicate which ones you can see and which ones you can't. That's why you HAVE to click on the squares. And if you click on white squares, it'll (wrongly) think you've visited sites you haven't. 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.
So that's why they can't "just render it outside the viewport." For sources, see the other comments by folks with good info.
- duskwuff 3y ago> 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.