There is no privacy clause in the constitution.
That's because Thomas, like Scalia, is an idiot. They both claimed to be "originalists" which, if they were to follow that meaning, would clearly mean the right to privacy which is covered under the 9th Amendment. The one which says, "We can't list every single right the people have so we're making this catch-all amendment to cover things. Just because we don't list it in this document doesn't mean you don't have it."
When the crown was routinely going through people's correspondence, or barging into homes and seeing what was there, how could one not understand the Founding Fathers wanted the people to both be secure in their homes and possessions as well as have the right to privacy in their lives?
The Constitution is a restriction on the government over the people. To not grasp that one's privacy is inherent in that limitation renders ones intelligence in doubt.