I think it works by labelling something like half the images, but doesn't tell you which is which. At least that's how the older text recaptcha stuff worked - y

I think it works by labelling something like half the images, but doesn't tell you which is which. At least that's how the older text recaptcha stuff worked - you could easily identify the pre-labelled text by the kind of distortions they used and just enter any old gibberish for the rest. So actually the training stuff is extra work beyond just classifying you as human