A Taxonomy of Privacy


"A Taxonomy of Privacy" is a work by Daniel J. Solove which attempts to order the different harms that may arise from infringements in privacy. Solove based this taxonomy on tort scholar William Prosser's work, who distinguished four different types of harmful activities under the privacy blanket:

  • Intrusion upon the plaintiff’s seclusion or solitude, or into his private affairs.
  • Public disclosure of embarrassing private facts about the plaintiff.
  • Publicity which places the plaintiff in a false light in the public eye.
  • Appropriation, for the defendant’s advantage, of the plaintiff’s name or likeness.

Solove decided to do this taxonomy since privacy is a right which is, to this day, ill-defined and vague, giving free speech advocates to upper hand in right to free speech - right to privacy disputes.

Under US law, there are two exemptions for “unwarranted invasion of personal privacy.”, enshrined in the Freedom of Information Act:

  • Exempting “personnel and medical files and similar files the disclosure of which would constitute a clearly unwarranted invasion of personal privacy”.
  • Exempting disclosure of “investigatory records compiled for law enforce- ment purposes that “constitute an unwarranted invasion of personal privacy” at open meetings.

The journal makes mention to Warren & Brandeis' famous article titled The Right To Privacy, where the authors define a breach to injury as an "injury to the feelings", or what is defined in the United States as a "dignitary harm". That includes incivility, lack of respect, emotional angst, and harm to one's reputation (defamation).

The taxonomy

Solove's taxonomy is split into four categories:

  • Information collection
  • Information processing
  • Information dissemination
  • Invasion

Those four categories are subsequently split into further categories:

  • Information collection
    • Surveillance
    • Interrogation
  • Information processing
    • Aggregation
    • Identification
    • Insecurity
    • Secondary use
    • Exclusion
  • Dissemination of information
    • Breach of confidentiality
    • Disclosure
    • Exposure
    • Blackmail
    • Appropriation
    • Distortion
  • Invasion
    • Intrusion
    • Decisional interference

Information collection


“What is the harm if people or the government watch or listen to us? Certainly, we all watch or listen, even when others may not want us to, and we often do not view this as problematic. However, when done in a certain manner—such as continuous monitoring—surveillance has problematic effects. For example, people expect to be looked at when they ride the bus or subway, but persistent gawking can create feelings of anxiety and discomfort.”

Surveillance in the Age of Information could alter people's behaviour to a very large extent, in the same way that Jeremy Bentham's Panopticon can. There is the risk of a "chilling effect" so powerful, that it could alter the way that people behave in society, out of fear of being constantly monitored.

In the case of Kyllo v. United States[1], it was established that the use of thermal imaging equipment by the police was only permissible with a warrant.

The above case is contrasted to to Florida v. Riley, where the court said that if something is visible from a public vantage point, then a reasonable expectation of privacy doesn’t exist.

In United States v. Knotts[2], the court stated:

“The secrecy paradigm: privacy is tantamount to complete secrecy, and a privacy violation occurs when concealed data is revealed to others. If the information is not previously hidden, then no privacy interest is implicated by the collection or dissemination of the information.”


Interrogation is a means of acquiring information through coercion, constituting a privacy harm, even if the information is not made available to third parties:

"Interrogation resembles intrusion in its invasiveness, for interrogation is a probing, a form of searching. Like disclosure, interrogation often involves the divulging of concealed information; unlike disclosure, interrogation can create discomfort even if the information is barely disseminated. [...] However, for interrogation generally, the compulsion need not be direct; nor must it rise to the level of outright coercion. Compulsion can consist of the fear of not getting a job or of social opprobrium."

Information processing


Aggregation is defined as:

"[...]the gathering together of information about a person. A piece of information here or there is not very telling. But when combined together, bits and pieces of data begin to form a portrait of a person. The whole becomes greater than the parts.This occurs because combining information cre- ates synergies. When analyzed, aggregated information can reveal new facts about a person that she did not expect would be known about her when the original, isolated data was collected.”

There exist instances of information aggregation which could serve a positive purpose, for example when Amazon.com collects information on a consumer's recent purchases, and advertises relevant products on their home page.

In United States Department of Justice v. Reporters Committee for Freedom of the Press[3], the US courts recognised aggregation as a violation of a privacy interest.

In addition, the disclosure of FBI rap sheets was an invasion of privacy within an exemption of the Freedom of Information Act (FOIA):


Identification is different to aggregation as it links to the real person, and not just the digital:

“[...]there can be extensive aggregations […] in many databases, but these aggregations might be rarely connected to[…] her day-to-day activities. This is […] high aggregation and low identification. On the flip side, one can have high identification and low aggregation, such as in a world of checkpoints, where people constantly have to show identification but where there are few linkages to larger repositories of data about people.”

Identification documents have some benefits, like reducing the chance of fraud and increasing accountability, as well as deterring misleading political ads. However, the issue remains that it demeans dignity by reducing individual to a list of traits and characteristics.

In B. v. France[4], a male to female transsexual sought to change her documentation to reflect her new, female, name. The court concluded: “as a result of the frequent necessity of disclosing information concerning her private life to third parties, suffered distress which was too serious to be justified on the ground of respect for the rights of others.”

In addition, identification limits a person's ability to remain anonymous:

"Anonymity and pseudonymity protect people from bias based on their identities and enable people to vote, speak, and associate more freely by protecting them from the danger of reprisal.”


Insecurity is not about a privacy harm already inflicted on someone, but about negligence leading to potential future harms.

Courts have sometimes recognised it as privacy harm, as was the case in Whalen v. Roe[5], where the court said that the constitutional right to privacy also extended to the “individual interest in avoiding disclosure of personal matters.”

However, there are still issues with its perception as a modern harm, evidenced in the case of Board of Education v. Earls[6]. A school district in Oklahoma adopted a drug testing policy that required all middle and high school students to undergo drug testing before participating in any extracurricular activity. The Supreme Court upheld the testing. The court did not distinguish between disclosure and insecurity, with the former being the deliberate leakage of information, and the latter leaving that information vulnerable for future harm.

Secondary use

Secondary use is defined as the use of data for a purpose not related to the one the data subject agreed to share their data for:

“The potential for secondary use generates fear and uncertainty over how one’s information will be used in the future, creating a sense of powerless- ness and vulnerability. In this respect, secondary use resembles the harm created by insecurity.”


Exclusion is “the failure to provide individuals with notice and input about their records.” This reduces accountability for government bodies and other record holders of individuals:

“[…] a harm created by being shut out from participating in the use of one’s personal data, by not being informed about how that data is used, and by not being able to do anything to affect how it is used.”

Information dissemination

Breach of confidentiality

Disclosure and breach of confidentiality cause different kinds of injuries. The latter also breaks the trust in a special relationship: “[…[ the victim has been betrayed”.

The US Fourth Amendment does not cover breach of confidentiality as a harm.


In Whalen v. Roe[7], the court decided that the right to privacy also includes interest in avoiding disclosure of personal matters.

Disclosure differs from breach of confidentiality because the harm in disclosure is the damage to reputation; harm with breach of confidentiality is the violation of trust.


“[…] the exposing to others of certain physical and emotional attributes about a person. These are attributes that people view as deeply primordial, and their exposure often creates embarrassment and humiliation. Grief, suffering, trauma, injury, nudity, sex, urination, and defecation all involve primal aspects of our lives—ones that are physical, instinctual, and necessary. We have been socialized into concealing these activities.”

Increased accessibility

In the case of United States Department of Justice v. Reporters Committee for Freedom of the Press[8], the court stated that:

“[...]there is a vast difference between the public records that might be found after a diligent search of courthouse files, county archives, and local police stations throughout the country and a computerized summary located in a single clearinghouse of information.”


“[…]the use of one’s identity or personality for the purposes and goals of another. Appropriation, like the privacy disruptions of disclosure and distortion, involves the way an individual desires to present herself to society.”


“[…]the manipulation of the way a person is perceived and judged by others, and involves the victim being inaccurately exposed to the public.”

This is primarily covered by defamation laws: libel and slander, and the "false light" tort.

Distortion differs from disclosure because distortion information is false and misleading.



Warren & Brandeis define intrusion as a cause of action when one intrudes “upon the solitude or seclusion of another or his private affairs or concerns” if the intrusion is “highly offensive to a reasonable person.”

Intrusion differs from other harms as it interrupts an individual’s day-to-day activities.

“In particular, intrusion often interferes with solitude, the state of being alone or able to retreat from the presence of others. Indeed, Warren and Brandeis wrote from a tradition of solitude inspired by Ralph Waldo Emerson, Henry David Thoreau, and Emily Dickinson.”

Decisional interference

Different from intrusion, as intrusion has to do with unwanted incursion of another’s person and life, whereas decisional interference has to do with unwanted incursion by an authority such as the state into a person’s personal life decisions.

One of the most famous cases where decisional interference was referenced is the one of Lawrence v. Texas[9], where privacy was invoked when striking down legislation prohibiting homosexual relations between consenting adults.

“Liberty protects the person from unwarranted government intrusions into a dwelling or other private places. In our tradition the State is not omnipresent in the home. And there are other spheres of our lives and existence, outside the home, where the State should not be a dominant presence. Freedom extends beyond spatial bounds.”


  1. http://caselaw.lp.findlaw.com/scripts/getcase.pl?navby=CASE&court=US&vol=533&page=27
  2. http://supreme.justia.com/cases/federal/us/460/276/case.html
  3. http://supreme.justia.com/cases/federal/us/489/749/case.html
  4. http://www.pfc.org.uk/caselaw/B%20vs%20France.pdf
  5. http://caselaw.lp.findlaw.com/scripts/getcase.pl?navby=CASE&court=US&vol=429&page=589
  6. http://caselaw.lp.findlaw.com/scripts/getcase.pl?court=US&vol=000&invol=01-332
  7. http://caselaw.lp.findlaw.com/scripts/getcase.pl?navby=CASE&court=US&vol=429&page=589
  8. http://supreme.justia.com/cases/federal/us/489/749/case.html
  9. http://supreme.justia.com/cases/federal/us/539/558/case.html