Google's already doing it with captcha: https://security.stackexchange.com/questions/78807/how-does-googles-no-captcha-recaptcha-work https://security.stackexch

Google's already doing it with captcha: https://security.stackexchange.com/questions/78807/how-does-googles-no-captcha-recaptcha-work https://security.stackexchange.com/questions/78807/how-does-... But does Facebook track user during everyday session or just during some validation-action?