These things are actually ways to get humans to train the company's algorithm to recognize things. (Captchas are just another way to make money while also supposedly keeping the bots out.) If humans have trouble categorizing, then the algorithm is going to be unable to choose, either, and just take the human's word for it most of the time.
what i hate most about this is I feel like i do both answers, do all the squares even if it has a few pixels of the item. And some I wont click on the square if its only a little bit and I literally get the website to tell me "you're wrong, Try again dumbass".
I wish they would tell me how and why i was wrong. I know it doesnt really matter in the long run, but when i'm in the moment, i feel retarded and i really want the bot system to tell me why my answer was wrong.
You can Google it for a ton of articles on it, it's hardly a secret that Google has been using people to train its algorithms, but here's one of the first hits.
The whole point of capcha is just taking what ever people answer it with and let them in. So, even if you don't check them, you'd be alright miost of the time, But if you do check them, nothing much other than you getting through happens most of the time.
But of course, sometime the capcha bot fucks up because there wasn't enough answer in the pool for them so yeah, it might fuck with you sometime.