If you run a whitelist firewall, you never see CAPTCHA's. The vast majority on the internet have nothing to do with the website you're visiting. When the website cannot redirect you to the CAPTCHA host site, it just continues on to the intended destination. The only way I ever see a CAPTCHA is if it is hosted on the same server as the site I am trying to visit, and that is very nearly never. I bet the vast majority of them are actually some advertiser collecting more data to mine in addition to whatever fingerprinting they can collect. Ads only work by opening a hidden frame that is basically another browser tab where you then visit the ad server's website. This is no different than visiting them in a browser tab. They can access everything available to fingerprint. If you're using anything Google controls that means they know everything about you down to how dirty your underwear is right now. /s^÷2^