Our second perspective on privacy then steps back from the codification of privacy and examines arguments for and against privacy—the motivation for protecting or curtailing privacy. This helps us to not only understand why we may want privacy, but also what we might lose without privacy. Is privacy something valuable worth incorporating into technology?
With both the historic backdrop and privacy motivations in mind, we then present contemporary conceptualizations of privacy. We will see that there are many views on what privacy is, which can make it difficult to understand what someone is referring to when talking about “privacy.” Precision is important when discussing privacy, in order to ensure a common understanding rather than arguing based on diverging perspectives on what privacy is or ought to be. The discussion of different conceptualizations and understandings of privacy is meant to help us evaluate the often nuanced privacy implications of new technologies.
2.1 CODIFYING PRIVACY
There is certainly no lack of privacy definitions—in fact, this whole chapter is about defining privacy in one way or another. However, at the outset, we take a look at definitions of privacy that have received broader societal support, i.e., by virtue of being actually enshrined in law. This is not meant as legal scholarship, but rather as an overview to what are considered fundamental aspects of privacy worth protecting.
2.1.1 HISTORICAL ROOTS
Privacy is hardly a recent fad. Questions of privacy have been in the focus of society for hundreds of years. In fact, references to privacy can already be found in the Bible, e.g., in Luke 12(2–3): “What you have said in the dark will be heard in the daylight, and what you have whispered in the ear in the inner rooms will be proclaimed from the roofs” [Carroll and Prickett, 2008]. The earliest reference in common law1 can be traced back to the English Justices of the Peace Act of 1361, which provided for the arrest of eavesdroppers and peeping toms [Laurant, 2003]. In 1763, William Pitt the Elder, at that time a member of the English parliament, framed in his speech on the Excise Bill the privacy of one’s home as follows [Brougham, 1839]:
The poorest man may in his cottage bid defiance to all the forces of the Crown. It may be frail—it’s roof may shake—the wind may blow through it—the storm may enter—the rain may enter—but the King of England cannot enter!—all his forces dare not cross the threshold of the ruined tenement.
One of the earliest explicit definitions of privacy came from the later U.S. Supreme Court Justice Louis Brandeis and his colleague Samuel Warren. In 1890, the two published the essay “The Right to Privacy” [Warren and Brandeis, 1890], which created the basis for privacy tort law2 in the U.S. legal system. They defined privacy as “the right to be let alone.” The fact that this definition is so often quoted can probably be equally attributed to it being the first legal text on the subject and being easily memorizable. While it encompasses in principle all of the cases mentioned previously, such as peeping toms, eavesdroppers, and trespassers, it is still a very limited definition of privacy. Warren and Brandeis’ defintion focuses on only one particular “benefit” of privacy: solitude. As we will see later in this chapter, privacy has other benefits beyond solitude.
Probably the most interesting aspect of Warren and Brandeis’ work from today’s perspective is what prompted them to think about the need for a legal right to privacy at the end of the 19th century:
Recent inventions and business methods call attention to the next step which must be taken for the protection of the person, and for securing to the individual what Judge Cooley calls the right ‘to be let alone.’ …Numerous mechanical devices threaten to make good the prediction that ‘what is whispered in the closet shall be proclaimed from the house-tops’ [Warren and Brandeis, 1890].
Figure 2.1: The Kodak Camera. George Eastman’s “Snap Camera” made it suddenly simple to take anybody’s image on a public street without their consent.
In this context, Warren and Brandeis’ quote of Luke 12(2–3) (in a translation slightly different from the Bible [Carroll and Prickett, 2008]) sounds like an prescient description of the new possibilities of mobile and pervasive computing. Clearly, neither the Evangelist Luke nor Warren and Brandeis had anything like modern mobile and pervasive computing in mind. In Warren and Brandeis’ case, however, it actually was a reference to a then novel technology—photography. Before 1890, getting one’s picture taken usually required visiting a photographer in their studio and sitting still for a considerable amount of time, otherwise the picture would be blurred. But on October 18, 1884, George Eastmann, the founder of the Eastman Kodak Company, received U.S.-Patent #306 594 for his invention of the modern photographic film. Instead of having to use a large tripod-mounted camera with heavy glass plates in the studio, everybody could now take Kodak’s “Snap Camera” (see Figure 2.1) out to the streets and take a snapshot of just about anybody—without their consent. It was this rise of unsolicited pictures, which more and more often found their way into the pages of the (at the same time rapidly expanding) tabloid newspapers, that prompted Warren and Brandeis to paint this dark picture of a world without privacy.
Today’s developments of smartphones, wearable devices, smart labels, memory amplifiers, and IoT-enabled smart “things” seem to mirror the sudden technology shifts experienced by Warren and Brandeis, opening up new forms of social interactions that change the way we experienced our privacy in the past. However, Warren and Brandeis’ “right to be let alone” looks hardly practical today: with the multitude of interactions in today’s world, we find ourselves constantly in need of dealing with people (or better: services) that do not know us in person, hence require some form of personal information from us in order to judge whether such an interaction would be beneficial. From opening bank accounts, applying for credit, obtaining a personal yearly pass for trains or public transportation, or buying goods online—we constantly have to “connect” with others (i.e., give out our personal information) in order to participate in today’s life. Even when we are not explicitly providing information about ourselves we constantly leave digital traces. Such traces range from what websites we visit or what news articles we read, to surveillance and traffic cameras recording our whereabouts, to our smartphones revealing our location to mobile carriers, app developers and advertisers. Preserving our privacy through isolation is just not as much of an option anymore as it was over a 100 years ago.
Privacy as a Right
Warren and Brandeis’ work put privacy on the legal map, yet it took another half century before privacy made further legal inroads. After the end of the Second World War, in which Nazi Germany had used detailed citizen records to identify unwanted subjects of all kinds [Flaherty, 1989], privacy became a key human right across a