could you show us an example of what it is that google's showing (and what you want it to show)? Generally with blogs, you want people to be able to read (and thus, search for) the content. If you want to limit content access to a certain group of people, I would suggest using password protection (or something similar) and not sending the data from the server until they have validated their identity. Then have your iframe only show the content that was sent, otherwise have a generic iframe with default content that search engines (and unregistered users) can look through.