What’s ironic is that the main purpose of reCAPTCHA v2 is to train ML models. That’s why they show you blurry images of things you might see in traffic.

AFAIK the way it works is that of the 9 images, something like 6 are images the system knows are True or False, and another 3 are ones it is being trained on. So, it shows you 9 images and says “tell me which images contain a motorcycle”. It uses the 6 it knows to determine whether or not to let you pass, and then uses your choices on the other 3 to train an ML model.

Because of this, it takes me forever to get past reCAPTCHA v2, because I think it’s my duty to mistrain it as much as possible.