http://www.usconstitution.net/constnot.html#privacy
Things not in the Constitution
The Right To Privacy
The Constitution does not specifically mention a right to privacy.
However, Supreme Court decisions over the years have established that the right to privacy is a basic human right, and as such is protected by virtue of the 9th Amendment. The right to privacy has come to the public’s attention via several controversial Supreme Court rulings, including several dealing with contraception (the Griswold and Eisenstadt cases), interracial marriage (the Loving case), and abortion (the well-known Roe v Wade case). In addition, it is said that a right to privacy is inherent in many of the amendments in the Bill of Rights, such as the 3rd, the 4th’s search and seizure limits, and the 5th’s self-incrimination limit.
Good Synopsis
I was merely providing an example of the supreme court actively allowing the government to violate our explicitly stated right to not have our private property seized on a whim. A court that would do that might do ANYTHING regarding an implied, but not explicitly stated, right such as privacy.
And I still don't agree that there should be any expectation of privacy regarding things that one publicly posts on web-site(s) for millions of other people to read. If you want to keep something private, keep it on your person, in your house, or amongst your papers and effects, don't shout it from a twenty-first century roof-top like "Facebook".