[talldayo]

> You would have hard time seeing this with your own eyes but if there are 100 people who did 100 recaptchas each, then the algorithm will be able to know which recpatchas were solved by which person.

Perhaps, but if tracking people across sites is your goal then Google would be much better served with hardware fingerprinting or cookie stashing.

[PrimaryAlibi]

It's fact that it's possible, the question is just if Google is doing it. I know some apps that have been proven to track mouse movement to identify users and prevent botting. They want to identify users because it's against ToS to have multiple accounts and also to prevent banned users from making new accounts. Tracking mouse movement is extremely accurate way to uniquely identify users. Google would have no problems doing this if they wanted to, the question is just if they are doing that. I think it would be coping to say they aren't but that's my opinion based on my perspective on big tech and google.