“Privacy” is a word of many meanings. The meaning that is most relevant to this essay is secrecy—the interest in concealing personal information about oneself. But I need to distinguish between a person’s pure interest in concealment of personal information and his instrumental interest, which is based on fear that the information will be used against him. In many cultures, including our own, there is a nudity taboo. Except in the sex industry (prostitution, striptease, pornography, and so forth), nudist colonies, and locker rooms, people generally are embarrassed to be seen naked by strangers, particularly of the opposite sex, even when there are no practical consequences. Why this is so is unclear; but it is a brute fact about the psychology of most people in our society. A woman (an occasional man as well) might be disturbed to learn that nude photographs taken surreptitiously of her had been seen by a stranger in a remote country before being destroyed. That invasion of privacy would not have harmed her in any practical sense. Yet it might cause her at least transitory emotional distress, and that is a harm even if it seems to have no rational basis (in that respect it is no different from having nightmares after watching a horror movie—another emotional reaction that is real despite being irrational from an instrumental standpoint). But if the stranger used the photos to blackmail her, or, in an effort to destroy her budding career as an anchorwoman for the Christian Broadcasting System, published the photos in Hustler magazine, she would have a different and stronger grievance.
In many cases of instrumental concealment of personal information, the motive is disreputable (deceptive, manipulative): a person might want to conceal his age, or a serious health problem, from a prospective spouse or his criminal record from a prospective employer. But the motive is not disreputable in all cases; the blackmailed woman in my example was not trying to mislead anyone in resisting the publication of the photos.