The word "privacy" not in the Constitution? Does it need to be?
Read the Ninth Amendment carefully, noting what the word "enumeration" means.
The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people.
What say you?
Privacy is a human construct which can be used or misused just like many things. Perhaps because it is so human mostly because of learned behaviour it will always cause troubles for some.