This is interesting :). OpenPhoto doesn't have the concept of "users". Any user can sign in (at the moment) with BrowserID which basically says that the user v

This is interesting :). OpenPhoto doesn't have the concept of "users". Any user can sign in (at the moment) with BrowserID which basically says that the user viewing owns a given email address. This allows anyone to sign in to any OpenPhoto site - without having an "OpenPhoto" account. From there all permissions are based on email address. I can give any user access to any photo by their email address. Not sure what you mean by giving Flickr permission to look at a photo. If you give an app permission to your photos that's done via OAuth and you can revoke that token at any time.