It doesn't seem to be fundamentally different than reCAPTCHA. They will probably replace the click-this-checkbox box with a set of elements already on the hosted page. Only indexing a page's HTML isn't good enough -- it's better to also know how people interact with the HTML. Unfortunately, as soon as they click a link on Google, Google is no longer invited to the party, and is blind to how the user interacts with the page.

The next best thing a search company can do is have every website willingly track their users' mouse and key movements, and then willingly send all of that data to the company's inbox. In return, Google provides them with a binary classifier trained on all of the user click-stream/click-move data which determines whether or not the user is a bot!

It's an OK deal for the website owner; it's a great deal for Google. Not to mention, the user is now sending anonymous data to Google, at the expense of the website's Privacy Policy.

Google gets website owners to willingly install live-cameras on every corner of their website, and then willingly send over all of the footage, in exchange for "protection" from bots. Cough The Government gets citizens to willingly fill out lengthy tax forms, and then willingly send over a bunch of money, in exchange for "protection" from criminals. Cough

why are you implying that taxation is somehow a protection racket? That's a pretty radical notion wrapped in a matter-of-fact language. Strikes me as a bit dishonest. Taxation pays for plenty of things besides police and military.

Agreed. The documentation page [1] has much more information.

[1] https://developers.google.com/recaptcha/docs/invisible

Instead of the user having to click the "I am not a robot" checkbox, then the submit button (or w/e), this basically binds clicking the submit button to reCAPTCHA. So whatever checks clicking "I am not a robot" would run are instead done automatically when submitting.

No idea how the additional prompts (e.g. "select the parts of the image with a street sign") are shown nicely in this "invisible" UX though.

They are shown in a lightbox in the middle of a page.

Here is the demo: https://www.google.com/recaptcha/api2/demo?invisible=true

To get the actual verification process open in incognito mode.

> This is so confusing.

Really?

> It doesn't explain how it works nor a demo page

Imagine a web form without reCaptcha. Do you really need a demo of that?

> nor the reason behind why it went invisible.

Because Recaptcha had an annoying, bad, terrible UX.

You have done nothing to answer the GP.

How does Google determine if the captcha should be shown?

What are the "adaptive captchas" that are shown to suspect users? A demo would do a great job here.

How does an invisible captcha "create value by applying human bandwidth" if the premise is that humans never see the captcha?

I also find it confusing. No need to be rude.