What Is Privacy? The Answer Has Been Changing for Decades

This post is in partnership with History Today. The article below was originally published at History Today.

If ongoing unease in the United States about the Facebook/Cambridge Analytica data scandal tells us anything, it is that the privacy to which digital citizens believed they were rightfully entitled was not in fact the privacy they possessed. Those who posted the contents of their lives on social media were outraged to discover their vulnerability to powerful data brokers, not to mention the specific uses to which their data was put, including political targeting and voter manipulation. Nothing barred a shady commercial outfit from siphoning off users’ “private” information in ways they had not been able to anticipate — and had not, therefore, taken adequate precaution against.

This gap between the imagined and actual boundaries around our private lives has been the leitmotif of modern privacy debates. Indeed, the most consistent thread in that history has been the concept’s fundamental instability in the face of social and technological change.

Commonsense understandings about privacy in the U.S., for example, were once closely tied to property lines and one’s physical person or surrounds: in the Fourth Amendment’s language, citizens’ right to “be secure in their persons, houses, papers and effects.” This made it relatively easy to determine when and whether one’s private boundaries had been breached. But, in the late 19th century, those boundaries were becoming more porous, the work of a commercial, mass-mediated, technologically sophisticated and information-hungry society. Ideas about the private self, as a consequence, became less fixed, too.

For example, telegraph cables and telephone lines — and even the humble postcard, first available for purchase in 1873 — made private communications speedier and more convenient, but also more open to the eyes and ears of others. Simultaneously, “instantaneous photography” and an aggressive commercial press were making private affairs newsworthy and saleable. This was at the root of Henry James’ lament, in 1888, about “the devouring publicity of life, the extinction of all sense between public and private.” James, along with other members of the urban bourgeoisie, would come to realize that private men and private residences were not the fortresses they were once presumed to be.

The trespasses of the new media were virtual rather than physical, but they were experienced as trespasses nonetheless. Indeed, as invasions of privacy became less tangible, they would transform the way many Americans thought about the right to security “in one’s person.” What about the right to one’s image and reputation, even to one’s personality, in a mass-mediated world? Might “privacy” encompass this sort of entity, too?

According to the Boston lawyers Samuel Warren and Louis Brandeis, who authored a landmark article in the Harvard Law Review on the “Right to Privacy” in 1890, novel forces — “instantaneous photography” and a “prurient newspaper enterprise” — had “invaded the sacred precincts of private and domestic life.” The two endorsed a broader version of privacy than mere property rights by calling for a shield around something they called the “inviolable personality” or “the right to one’s personality.” Their explicit target was the new “mechanical devices” that “threatened to make good the prediction that ‘what is whispered in the closet shall be proclaimed from the house-tops.'” These technologies, they urged, fully warranted “the next step which must be taken for the protection of the person.”

It was not only an elite concern. Some of the first claims to a modern right to privacy were launched by ordinary plaintiffs — often women — whose images were used, without their consent, to advertise soap or cigarettes. In 1902, in a New York case that made headlines, Abigail Marie Roberson lodged such a complaint against Franklin Mills Flour. Roberson cited the making of 25,000 “lithographic prints, photographs, and likenesses” of herself without her knowledge, which were then displayed in stores, saloons and other public venues. (She had only learned of the advertising campaign when she glimpsed her face on a neighbor’s bag of flour.)

The questions that lawsuit raised still linger: who had the right to possess, consume or circulate one’s image? What parts of one’s person were truly one’s own? New technologies and social practices, as well as new ideas about personal borders, changed privacy from a propertied concept into one equally concerned with ephemeral matters of personality.

Cameras and newsprint would not be the last technologies to spark debates about the proper boundaries around the individual, or to work changes in the definition of personal privacy. In the early 20th century, techniques for documenting individual lives, such as birth certificates, passports, fingerprinting and Social Security numbers, raised similar questions, this time not about publicity or reputation, but about identification and tracking.

What would happen to personal, often sensitive, information, such as address, birth date and work history, once it was recorded by the administrative state or private gatekeepers, like the credit and insurance industries? As files swelled in the 20th century and their contents became more consequential for individuals, “privacy” would revolve more around personal data — a shift that would only intensify with the arrival of computerization.

Further developments would unsettle the boundary between the public and private person by mid-century. During the Cold War, Americans not only witnessed the arrival of a full-blown national security state. They were also increasingly subject to intimate prying in their daily lives from psychological experts with ambitions to get inside their minds, emotions and psyches, whether in therapists’ offices, suburban communities, white-collar workplaces, school classrooms or the consumer market.

Subliminal advertising, motivational research and personality testing — precursors of Cambridge Analytica’s psychographic techniques — all triggered controversies in the 1950s and 1960s. Fears about “brain watching” focused on the shifting line between self and society and prompted novel claims to psychological privacy.

Echoes of old debates about publicity, documentation and invasion sound regularly today. We are well aware of the rapid spread and easy accessibility of embarrassing details in the form of cyberbullying and “revenge porn.” Likewise, the perils inherent in our own stored biographies have triggered policy discussions about anonymization and the “right to be forgotten.” The possibility that we might be influenced or “nudged” into decisions by manipulators of our own data has once again become a live issue.

That we recognize these quite different developments as threats to privacy is only possible because the concept of privacy has itself shifted over time, expanding in response to a society that has often appeared bent on exposing its members to view. As in the past, we do not stop to consider what privacy consists of until it seems — just like that — to fall victim to unimagined breaches. And, as in the 19th century, when wiretapping and candid photography were new, today’s technologies of data-harvesting and scraping are already transforming our beliefs about the borders of our private selves.

Sarah E. Igo is the author of The Known Citizen: A History of Privacy in Modern America (Harvard, 2018).