In the late 18th century, the word 'privacy' did not mean that same as it does today. Unlike today where we think of the word 'private' as pertaining to anything which either an individual or consenting adults do when alone, back during the time of our Founding Fathers, the word privacy had a much narrower meaning. It only covered personal things pertaining to one's body, as in 'bodily functions'. In other words, when someone in the late 1700's asked for some 'privacy' it meant that they had to relieve themselves (i.e. go the the bathroom). This is why outhouses were called 'privies' back then, derived from the word 'privacy'. It was only later, after the development of indoor plumbing that the word 'privy' was no longer needed and so the meaning of the word slowly evolved into the broader meaning that it has today. When the Constitution was written, along with the Bill of Rights, it would have been inappropriate, not to mention even a bit scandalous, to have used the word 'private' or 'privacy' when proposing the wording for the 4th Amendment. So we ended up with the more flowery sounding "The right of the people to be secure in their persons, houses..." which most all Constitutional scholars agree that this means, in today's definition, that we have a "Right to Privacy...".
I bring this up because Rick Santorum is promoting the idea that since the Constitution never actually used the word "privacy" anywhere in the main document nor even in the Bill of Rights, that therefore Privacy is NOT a right guaranteed to Americans and thus it's OK for the government to invade our homes to see if we're performing unnatural sex acts or even using contraceptives. Of course if someone suggests that perhaps it's a good idea for everyone have health insurance, that's Unconstitutional, but he wants to arrest people for what they do in their bedrooms behind closed doors and he claims it will be Constitutional since he can't find the word "privacy" spelled-out anywhere.
http://abcnews.go.com/blogs/politics/2012/01/santorum-explains-06-loss-still-supports-state-right-to-outlaw-contraception/

OCU