Usually what happens instead is that you get an unsolvable challenge. Well, not always unsolvable, occasionally the algorithm has mercy and lets you through after minutes of suffering. But it's not really worth trying.

I've been stuck in reCAPTCHA hell before where I swear they were sent to specifically discourage someone from continuing.

"Select All the Crosswalks" but then, they have an image of the rumblestrips cut into the side of highways (that warn you when you veer off road) when, photographed correctly "look like" crosswalk stripes. Didn't select it because it's not a crosswalk, failed. Then everything else is "Select the bicycles" with images of motorcycles too. Does Google know the difference between the two? I do. Still failed, maybe I should have selected the motorcycles also.

And don't even get me started on the ones where you have like 4 pixels of an image in another square. Do you select it as well? Part of the fire hydrant is in that square. When selecting the street lights, do you choose JUST the very clearly obvious ones, or do you select the small, out of focus ones in another square as well?

Usually at this point I just say, "fuck it" and find what I'm looking for elsewhere.