While it is true that the Constitution does not contain the word privacy, so too, does it not contain many other words, including the words slave or slavery, until the passage of the Thirteenth Amendment in which slavery was legally legislated out of existence. However, a careful reading of the Constitution and its amendments clearly indicates that citizens of this country do have the right to privacy, as demonstrated most particularly by the Fourth Amendment, "…to be secure in their persons," as well as in the Ninth Amendment, "The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people," in addition to other Amendments that allude to privacy, and the Constitution itself, which as the prevailing written document, is the Supreme Law of this land, which was specifically written to "…secure the Blessings of Liberty," of which one of the blessings of liberty, is the right to be secure in one's own thoughts as well as to be secure in one's own private possessions, and not to be subject to a government that violates those sacrosanct rights, without due process of the law.
The very people and governmental agencies that disparage the rights of the people of their privacy and to be secure in their possessions are almost always the very same people and governmental agencies that lack integrity, honesty, and transparency in their own affairs; and further bring both the worn-out shibboleth that the government needs to know everything about its people in order to protect those people, in which the sacrificing of their privacy is considered to be a fair trade. For all those that voluntarily relinquish their right to privacy, that is their prerogative, but when that privacy is unjustly taken from them, it is a violation of the Supreme Law of this land.
In regards to a world in which so much of what a given person does online or through their conversations and movement is now duly recorded, stored, collated, and utilized by high tech corporations of all types, this is, despite the terms and conditions of usage by the people of those high tech devices and their conduits, a direct affront to the privacy of the individual, whenever those individuals do not have the real power and the real choice to control or to own their private being in a manner in which they are the masters of their own persona, as opposed to having little or no control over their image, their postings, their movements, and their interactions with others.
Those that do not have control over their privacy in their person, have for all intents and purposes, morphed into something that is now public, and the more public that one's thoughts and images are, in which these formerly were private, the easier it is to be marketed to, to be propagandized to, to be manipulated by, and to be controlled. That is the case, whenever a given individual no longer has a sacred place to be in solitude, therefore having no sanctuary; and hence those without a sanctuary are no longer free or liberated, but are instead, bounded into a form of servitude.