part of Google's control of captcha also has to do with knowing who you are, so if you come to a site but google knows who you are and have a 99% surety you are

part of Google's control of captcha also has to do with knowing who you are, so if you come to a site but google knows who you are and have a 99% surety you are not a bot even if you act very botlike on that site you probably aren't going to get any problems.