http://certbot.iykpqm7jiradoeezzkhj7c4b33g4hbgfwelht2evxxeicbpjy44c7ead.onion/fa/pages/privacy
Currently, Certbot works with Let’s Encrypt by default, which, as of April 2016, has three documents that discuss its privacy practices for this information; the Let’s Encrypt Privacy Policy section on Subscribers, it’s Certification Practice Statement (which, as of April 2016, just references back to the Privacy Policy), and the Let’s Encrypt Subscriber Agreement (Section 4.1).