Private medical data - Google targeted ads

[l0st]

If the site asks the users to create an account and then log in with the account information then Google or any other search engine should not be able to access the private area, as they would need to know the passwords of all users to get their information.

Not sure if it is still th case, but Google used to require that one provide an actual account for indexing or the site is de-ranked in the results. So it's kinda like wanting to be in the phone book, but only if you'll give the phone company access to all of your data to be published in it.