A definition of privacy in 2,200 words

Privacy is definitely a slippery subject that eludes straightforward definitions. I have spent four or five months now trying to come up with a definition of privacy. It is an iterative process where each time I look I weave in further thoughts. Here’s how my attempts stand at the moment.

Before thinking about a definition of the term “privacy” it is necessary to make a distinction between “data protection” and “privacy”. These terms are sometimes used interchangeably in the literature; but that is misleading because it overlooks an important distinction between the two concepts. Data protection is not the same as privacy. The right to data protection and the right to be forgotten are procedural rights, whereas the right to identity and the right to privacy are substantive rights.

Procedural rights cover the rules, methods and conditions through which the substantive rights are enforced. Procedural requirements include things like transparency, accessibility and proportionality.

Privacy is commonly defined in terms of control and freedom. But the present researcher would add that privacy is also closely related to the concept of human dignity (Bloustein 1964). (Greene 2014) goes further and says that “privacy is said to be intimately related … to a host of other values, including freedom, intimacy, autonomy, integrity, respect, dignity, trust, and identity.”

(Westin 1967) defines privacy as “the claim of individuals, groups, or institutions to determine for themselves when, how and to what extent information about them is communicated to others”.  He says that privacy is “the ability of the individual to control the terms under which personal information is acquired and used”. This can be taken as a definition of informational privacy.

“Informational privacy in a normative sense refers typically to a non-absolute moral right of persons to have direct or indirect control over access to (1) information about oneself, (2) situations in which others could acquire information about oneself, and (3) technology that can be used to generate, process or disseminate information about oneself” (van den Hoven, Blaauw et al. 2014).

(Floridi 2014a p102) says that it is common to distinguish four kinds of privacy: physical privacy, mental privacy, decisional privacy, and informational privacy. For Floridi, informational privacy is the protection of personal identity; and that informational privacy is of primary importance.

We take privacy to be both a right of freedom from (which is well expressed by (Warren & Brandeis, 1890) as “the right to be let alone”; as well as a right of freedom to (self development).

(Curry 1997) describes Warren & Brandeis’ definition of privacy as the “right to be let alone” as “one of the earliest and most succinctly annunciated definitions of privacy”. This widely quoted definition frames privacy as a right. The judgment in Olmstead v. U.S., 277 U.S. 438 (1928) further expands on this in referring to privacy as “the most comprehensive of rights, and the right most valued by civilized men”.

Whilst a short & succinct definition of privacy may be doomed to failure, (because it would be too restrictive and would be likely to get out of date very quickly) attempts to map the ground covered by the concept of privacy have made significant progress.

(Koops, Newell et al. 2017) have developed a typology of privacy in which they categorise eight different types of privacy, across all of which they overlay informational privacy. They divide the eight categories between privacy types that are “Freedom from” (the right to be let alone): Bodily privacy, spatial privacy, communicational privacy, and proprietary privacy; and privacy types that are “Freedom to” (self development): Intellectual privacy, decisional privacy, associational privacy and behavioural privacy

One omission from their list is a category is privacy of counsel, the right to private consultation with counsel or the right not to have one’s legally privileged material subjected to surveillance.

A number of commentators acknowledge the difficulty of defining privacy, and the lack of consensus on a definition:

  • (Greene 2014) says that privacy is “a multifaceted concept which eludes easy definition”.
  • (Greenland 2013) says that “there is no single agreed definition of privacy in the literature”, recognising that this can be a strength: “a range of conceptions of privacy is valuable because it encompasses several issues”.
  • (Taylor, Floridi et al. 2017) acknowledge that “the concept of privacy is notoriously difficult to define and has varied and sometimes conflicting interpretations”.

(Gutwirth 2002) says “The notion of privacy remains out of the grasp of every academic chasing it. Even when it is cornered by such additional modifiers as “our” privacy, it still finds a way to remain elusive.”

Coming up with a definition of the term “privacy” is incredibly difficult; especially if one hopes to find an authoritative definition which will stand the test of time. Indeed (Hartzog, Selinger 2013) consider it to be a sisyphean task. Commenting on the concept of obscurity within the context of privacy, they say that “Discussion of obscurity in the case law remains sparse. Consequently, the concept remains under-theorized as courts continue their seemingly Sisyphean struggle with finding meaning in the concept of privacy” (Hartzog, Selinger 2013)

Scholars argue that the definitional attempt to clarify the privacy concept is nebulous, and that no universally accepted definitions have emerged (Bennett, 1992; Flaherty, 1989).

As the influential privacy scholar Alan Westin put it, privacy as a notion is “part philosophy, some semantics and much pure passion” (Westin 1967).


It is hardly surprising, therefore, that some commentators make a conscious decision to avoid even attempting to come up with a definition of the word, let alone trying to come up with a definitive description of what privacy is. It is, nevertheless, imperative that people do try to come up with a definition for a number of reasons. Two in particular are especially worthy of consideration:

  • Privacy is widely recognized as an important good that deserves protection. But what cannot be described, defined and understood cannot be defended or regulated. Hence, how the meaning of privacy is constructed in the first place has far-reaching implications for how privacy boundaries and behaviors are negotiated and potentially re-settled in light of a changing world. Arguably then, the understanding of the meaning content of the category of privacy holds the key to the future of privacy in the digital world (Bajpai, Weber 2017).
  • (Cannataci 2016b) believes that the existence and usefulness of an international legal framework for privacy is seriously handicapped by the lack of a universally agreed and accepted definition of privacy if we do not have a clear understanding of what we have agreed to protect: “While the concept of privacy is known in all human societies and cultures at all stages of development and throughout all of the known history of humankind it has to be pointed out that there is no binding and universally accepted definition of privacy”

Even if there were a universally agreed and accepted definition of privacy, another handicap is what Cannataci refers to as TPET: the Time, Place, Economy and Technology dimensions. For the passage of time and the impact of technology, taken together with the different rate of economic development and technology deployment in different geographical locations means that legal principles established fifty years ago (ICCPR) or even thirty-five years ago (e.g. the European Convention on Data Protection) let alone seventy years ago (UDHR) may need to be re-visited, further developed and possibly supplemented and complemented to make them more relevant and useful to the realities of 2016. (Cannataci 2016b)

Agre says that “One constant across this history is the notorious difficulty of defining the concept of privacy. The lack of satisfactory definitions has obstructed public debate by making it hard to support detailed policy prescriptions with logical arguments from accepted moral premises. Attempts to ground privacy rights in first principles have foundered, suggesting their inherent complexity as social goods” (Rotenberg, Agre 1998).

(Greene 2014) says that “privacy applies to a curious mix of disparate acts, events, things, states of mind, and information. We speak of privacy with regard to our body parts, personal papers, important life decisions, financial status, homes, genetic inheritance, past actions, and our physical selves even when out in public, to name just a few examples”.

(Finn, Wright et al. 2013) say that “privacy” has proved notoriously difficult to define.

One dictionary defines privacy as “the right to be free from unwarranted intrusion and to keep certain matters from public view” (Law 2015)

Privacy is commonly defined in terms of control and freedom. But the present researcher would add that privacy is closely related to the concept of human dignity. (Greene 2014) goes further and says that “privacy is said to be intimately related … to a host of other values, including freedom, intimacy, autonomy, integrity, respect, dignity, trust, and identity.”

(Reiman 1995) says “Privacy is the condition in which others are deprived of access to you” which he explains further as people being deprived of access to either some information about you or some experience of you.

(Tripathi, Tripathi 2010) says “Privacy can be defined as an individual’s freedom to decide to what extent he/she likes to share their intellectual, social and cultural life with others, or in other words to what extent others can invade into his/her private life”.

(Garoogian 1991) says that “Privacy, as the term is commonly used, means the unavailability to others of information about oneself”. She presents moral, legal and professional arguments for the protection of a patron’s privacy. (Garoogian 1991) picks out a number of definitions of privacy:

  • the claims of individuals …to determine for themselves when, how and to what extent information about them is communicated to others (BUCHANAN 1982)
  • the condition enjoyed by one who can control the communication of information about himself. (Lusky 1972)
  • selective control of access to the self or to one’s group (Altman 1976)
  • control over when and by whom various parts of us can be sensed by others. By “sensed” is meant simply seen, heard, touched, smelled or tasted. (Thompson 1975)
  • [the] right that certain steps shall not be taken to find out facts [private facts] and …[the] right that certain uses shall not be made of [these] facts. (Thompson 1975)
  • having control over information about oneself. (Decew 1987)

The right to privacy has arguably always been used to get to thorny and hard-to-define problems because it touches on various more concrete rights – those of autonomy and the right to intellectual freedom, freedom from surveillance and interference, and the right to behave in ways that may be inconvenient for the authorities. Edward Snowden says that “privacy is the fountainhead of all other rights” (Schrodt 2016).

Defining the elements of privacy, (Sturges 2002) outlined solitude, anonymity, bodily modesty, psychological integrity and confidentiality (in terms of shared information) as important components of privacy.

(Petronio, Altman 2002 p6) defines privacy, ‘‘as the feeling that one has the right to own private information, either personally or collectively.’’

(Greenland 2013 p223) says “privacy refers to notions such as an individual’s right to be respected, personal space, dignity and autonomy, as well as those aspects of a person’s life they wish to restrict access to or keep control of (McCullagh 2008)”.

The goal of privacy is not to protect some stable self from erosion but to create boundaries where this self can emerge, mutate and stabilize (Morozov 2014). The boundaries metaphor is used by a number of scholars such as (Altman 1977) and (Petronio, Altman 2002)

The right to privacy protects an interest that has been defined as a “personal condition of life characterised by seclusion from, therefore absence of acquaintance by the public” Norberto Nuno Gomesde Andrade IN (Ghezzi, Pereira et al. 2014)


(Mai 2016) believes that we need to shift away from definitions of privacy and look instead to models of privacy. He supplements Agre’s surveillance and capture models with a third model which he sees as being supplementary, namely the datafication model where data is deduced by predictive analytics.

In a library context privacy is thought of as a right to open inquiry.

The American Library Association defines a right to privacy in a library, whether physical or virtual, as “the right to open inquiry without having the subject of one’s interest examined or scrutinized by others” (American Library Association 2014).

(Caldwell-Stone 2012) defines users’ information privacy as the right to read and inquire anything, without the fear of being judged or punished.

These two statements, by trying to encapsulate a brief definition of library privacy are in many regards too restrictive because they seem to relate only to someone actively seeking out information.

Writing in the Intellectual Freedom Manual (American Library Association 2010), Deborah Caldwell-Stone says “Confidentiality exists when a library is in possession of personally identifiable information about library users and keeps that information private on their behalf”.

(Richards 2015 p95) argues for a certain kind of privacy, one which is different from tort privacy, which he refers to as “intellectual privacy”, and which he believes to be essential if we care about freedom of expression. Indeed, he says that privacy and (freedom of) speech are not conflicting values but are mutually supportive. The three most important elements of intellectual privacy that Richards identifies are:

  1. the freedom of thought;
  2. the right to read (and engage in intellectual exploration),
  3. and the right to communicate in confidence

and he acknowledges that all 3 elements are related and build on the others

(Richards 2015 p95) says that “intellectual privacy is the protection from surveillance or unwanted interference by others when we are engaged in the process of generating ideas and forming beliefs – when we’re thinking, reading and speaking with confidants before our ideas are ready for public consumption”.

(Richards 2015 p95) believes that because it is only comparatively recently that surveillance and monitoring has been happening in a big way, that intellectual privacy is under-developed and under-appreciated. Intellectual privacy is increasingly under threat, and constant assault.


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