We do not collect or store any information about you from our third party sign-in providers (Google, Twitter, GitHub and Facebook). The email address (if any) that you supply on the accounts page will not be shared.
The content that you create on ProtoPedia is public in the partial sense that anyone who knows the URL of the content has read access to it. This allows you to share content with others by giving them URLs. There is no directory service which would allow discovery by other means. However you should not regard the content as private, either, since guesses (possibly mechanized) are always possible. ProtoPedia content is somewhat like the content in public repositories on GitHub, but without any directory service. As at GitHub, you are encouraged to express your desires about sharing your content via a license.txt file at top level.