Privacy is an essentially contested concept. It evades a clear definition and when it is defined, scholars do so inconsistently. So, what are we to do now with this fractured term? Ryan Hagemann suggests a bottom up approach. Instead of beginning from definitions, we should be building a folksonomy of privacy harms:

Hagemann aims to route around definitional problems by exploring the spaces where our interests intersect with the concept of privacy, in our relations to government, to private firms, and to other people. It is a subtle but important shift in outlook that is worth exploring.

Hagemann’s colleague Will Wilkinson laid out the benefits of this kind of philosophical exercise, which comes to me via Paul Crider. Wilkinson traces it back to very beginnings of liberal thought, which takes a bit to wind up:

Hagemann is right to build privacy on the particularism of Wilkinson, Reid and Chisholm. Given the changing nature of technology, we should take a regular “inventory of things that we’re sure we know” about privacy and then build theories on top of it.
Indeed, privacy scholarship finds its genesis in this method. While many have gotten hung up on the rights talk in the “Right to Privacy”, Warren and Brandeis actually aim “to consider whether the existing law affords a principle which can properly be invoked to protect the privacy of the individual; and, if it does, what the nature and extent of such protection is.” The article looks to previous law to construct a principle for “recent inventions and business methods.” This is particularism applied to privacy.
Only a handful of court cases that are actually reviewed in the article, the most important of which is Marian Manola v. Stevens & Myers. Marian Manola was a classically trained comic opera prima donna that had a string of altercations with her company where Stevens was the manager. About a year before the case, the New York Times carried a story describing a dispute between Manola and another actor in the McCaull Opera Company. She refused to go on stage after the actor pushed her on stage and Benjamin Stevens, apparently “ignored her until she returned to her duty.” About a year later, Stevens set up the photographer Myers in a box, as a stunt to boost sales. Manola sued the both of them. Today, the case would be cited in the right to publicity literature.
Still, Warren and Brandeis were trying to survey the land of privacy harms and then build a principle on top of it.
Be it either particularism or methodism, these ways of constructing knowledge frame the moral ground, creating a field where privacy advocates and privacy scholars can converse. What unites these two groups, then, is their common rhetoric about the contours of  privacy harms. And so, what constitutes a harm is still the central question in privacy policy.