Navigating the Dataverse: Privacy, Technology ... - The ICHRP

Griswold set the pattern for one branch of interpretation of the right to privacy in Supreme
Court case law, which in the main focused on “decisional privacy” (Roessler’s first
category). Privacy appears as the right to choose, particularly in matters concerning
the body. 134
A second branch of case law commences with a ruling on wiretapping (Katz v. United
States), which overturned Olmstead. An FBI wiretap on a public telephone booth was
found illegal because (to paraphrase Justice Marshall Harlan in language that has
since become standard) in the circumstances in question a person has a “reasonable
expectation of privacy”. 135 This remains the test for privacy in cases involving
surveillance; but its most consistent effect (the “public” phone booth in this particular
case notwithstanding) has been to distinguish spatially between “public” and “private”
(i.e., the home). 136 The implication appears to be that an American’s home is his castle,
but the decision is clearly rooted in “local privacy” (Roessler’s second category), rather
than “informational privacy” (her third).
An American’s home is his castle, but the decision is clearly rooted in “local
privacy” rather than “informational privacy”.
The right to privacy in these cases derives from the Fourth Amendment to the US
Constitution, which says:
The right of the people to be secure in their persons, houses, papers, and
effects, against unreasonable searches and seizures, shall not be violated,
and no Warrants shall issue, but upon probable cause, supported by Oath
or affirmation, and particularly describing the place to be searched, and
the persons or things to be seized.
The amendment explicitly addresses property (hence the near-hypnotic return, in
the case law, to the privacy of the home), personal security and legality (warrants,
“affirmations”, specific instructions). The amendment includes a number of terms of art
that have provided excellent fodder for legal wrangling. What is a “reasonable” search
or seizure? What evidence indicates a “probable” cause to justify undertaking one?
The “reasonable expectation of privacy” is, of course, similarly open to subjective
interpretation. 137 As Daniel Solove points out, “reasonable expectation” sounds like a
moving target. 138 As surveillance becomes normalised, for example, expectations shift.
We know our online presence leaves a significant data-trail, but also that the full extent
and content of this data-trail is not known to us. Can we expect it not to be known to
134 Landmark cases include Loving v. Virginia, 388 U.S. 1 (1967); Stanley v. Georgia, 394 U.S. 557 (1969);
Roe v. Wade, 410, U.S. 113 (1973); Lawrence v. Texas, 539, U.S. 558 (2003).
135 Katz v. United States, 389, U.S. 347 (1967), concurring opinion of Justice Harlan.
136 Relevant cases include Kyllo v. United States [thermal-imaging devices to track movements within a
house violate privacy: “the Fourth Amendment draws a firm line at the entrance of the house”]; Florida v.
Riley [surveillance flights over greenhouses for marijuana plantations do not violate privacy: “as a general
proposition, the police may see what may be seen from a public vantage point where [they have] a right to
be”]; Dow Chemicals Co. v. United States [telescopic lenses on overflying craft are lawful]; United States v.
Karo [a tracking device in a home violates privacy]; United States v. Knotts [following a car on public roads
does not violate privacy]. See generally Solove (2009), 110–111; Nissenbaum (2010), 115–116.
137 Antonin Scalia described the Court’s case law as tautological, identifying “reasonable expectations”
since Katz, wherever they “bear an uncanny resemblance to the expectations that this Court considers
reasonable.” Cited in Solove (2009), 72.
138 Solove (2009), 72.
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