Katz Out of the Bag: The Diminishment of the Expectation of Privacy

The Supreme Court’s doctrine on the expectation of privacy was first stated in a concurring opinion by Justice John M. Harlan II in Katz v. United States (1967). The case involved a man who was arrested after making illegal wagers from a public phone booth after FBI agents used an electronic eavesdropping device to record his conversation. The Court threw out the conviction and held that what a person “seeks to preserve as private, even in an area accessible to the public, may be constitutionally protected.” Justice Harlan’s concurring opinion created a test – that was later adopted by the Court in Smith v. Maryland (1979) – for determining whether a government search is reasonable under the Fourth Amendment. This test contains two parts. First, “a person [must] have exhibited an actual (subjective) expectation of privacy,” and second, that “expectation [must] be one that society is prepared to recognize as ‘reasonable.’” The problem with this is the second part of the test. Americans are likely to expect less and less privacy as time goes by. Technological innovation has had a hand in causing society to expect less privacy. Americans by and large now expect that the government may be spying on them at any given time. Americans expect that the government is monitoring their phone calls and internet usage. As more advanced spy satellites and drones enable the government to spy on individuals at any time and in any place, society will inevitably lose any expectation of privacy. Why should a natural right be so dependent upon advances in technology? Why should a human being in the early twenty-first century have a less robust right to privacy than a human being in the eighteenth century? Why should human beings in the future have a less robust right to privacy than human beings do today?

In Kyllo v. United States (2001), the Court carved out a potentially greater sphere of privacy for the home. The case involved police using a thermal-imaging device – a camera that shows heat images – to detect heat from high-intensity lights used to grow marijuana. In a 5 to 4 decision that did not break according to party lines, the Court held that the use of a thermal-imaging device constitutes a search under the Fourth Amendment, and thus, requires a warrant. The Court stated that where “the Government uses a device that is not in general public use, to explore details of the home that would previously have been unknowable without physical intrusion, the surveillance is a ‘search’ and is presumptively unreasonable without a warrant.” The problem with this was stated in Justice John Paul Stevens’ dissenting opinion in which he points out:

Despite the Court’s attempt to draw a line that is “not only firm but also bright,” the contours of its new rule are uncertain because its protection apparently dissipates as soon as the relevant technology is “in general public use.” Yet how much use is general public use is not even hinted at by the Court’s opinion, which makes the somewhat doubtful assumption that the thermal imager use in this case does not satisfy that criterion. In any event, putting aside its lack of clarity, this criterion is somewhat perverse because it seems likely that the threat to privacy will grow, rather than recede, as the use of intrusive equipment becomes more readily available.  

Stevens also points out that at the time of the decision there had been thousands of thermal-imaging devices manufactured and that the device was “readily available for the public” in that it could be rented by anyone who wanted one from a half dozen national companies. If thermal-imaging scanners were not “in general public use” in 2001, it seems that they will be soon. Perhaps they already are.  

One of the greatest threats to privacy in the near future is likely to come from surveillance drones. Presently small drones can be purchased for $1,000, and larger drones which can operate in inclement weather can be purchased for $12,000. In 2012, Congress allocated $63.4 billion to allow the Federal Aviation Administration to modernize air traffic control systems and to expand airspace for unmanned drones within three and a half years. It would be foolish not to expect American skies to eventually be filled with both government and commercial drones. As drones begin to proliferate, the expectation of privacy both in public and in the home will be diminished by the terms of both Katz and Kyllo. In 2011, MIT researchers devised technology using microwaves that allows users to see through walls in real time. It is only a matter of time before technology like this is commonplace and employed by both government and commercial drones. As Americans become resigned to the fact that they do not have privacy even within their own homes, the Fourth Amendment will no longer apply to governmental use of drones employing technology to see through the walls of homes.  

In the totalitarian police state of George Orwell’s terrifying dystopian novel 1984, “nothing was your own except the few cubic centimeters inside your skull.” Unfortunately, technology could one day create a state of affairs where even the privacy of the thoughts of Americans is not protected by the Fourth Amendment. While using brain scans to determine whether an individual is telling the truth or what thoughts a person are thinking seem to be fanciful subjects more at home in science fiction stories than in American court rooms, advocates of new technologies claim that “mind reading” technology is on the horizon. One such technology is the Brain Electrical Oscillations Signature test (BEOS), which was developed by Champadi Raman Mukundan, an Indian neuroscientist. BEOS uses an EEG and proprietary software.

The software tries to detect whether, when the crime's details are recited, the brain lights up in specific regions – the areas that, according to the technology's inventors, show measurable changes when experiences are relived, their smells and sounds summoned back to consciousness. The inventors of the technology claim the system can distinguish between peoples' memories of events they witnessed and between deeds they committed.

While experts unanimously agree that the experimental evidence demonstrating the effectiveness of BEOS is dubious at best, this did not prevent an Indian court from using BEOS evidence in convicting a woman formurder in 2008.

Another potential “mind reading” technology is the functional magnetic resonance imaging (fMRI) scanner. The fMRI has the potential to be used as a more technologically advanced and more Orwellian polygraph:

Feroze B. Mohamed, an associate professor of radiology at Philadelphia's Temple University, conducted an experiment in which he instructed some test subjects to fire a pistol and then falsely answer questions about the event while undergoing fMRI. Compared to others who truthfully said they did not fire a weapon, the liars showed increased activity in twice as many brain regions, including those associated with memory, judgment, planning, sentence processing and inhibition. The findings lend credence to what we've all realized at one time or another: It takes a lot more effort to lie than to tell the truth.

While technology like BEOS and fMRI are likely nothing but “snake oil,” it hardly matters if the government eventually comes to believe that these devices or others like them are accurate. The Supreme Court addressed the use of polygraphs in UnitedStates v. Scheffer (1998). In that case, the Court was unwilling to formulate a rule that polygraph evidence should be inadmissible in American courts.  Therefore, there is no precedent that would necessarily rule out the use of “brain scanning” evidence in the future.

Assume for the moment that one day small handheld “brain scanners” become commonly used. Assume also that although “mind reading” is likely logically impossible, that these devices become widely accepted as accurate. In such a state of affairs, Americans will eventually stop believing that the expectation of the privacy within their own brains is reasonable. If the Court does not overturn the Katz test, then in this future “Brave New World,” the Court will be obliged to hold that human beings no longer have the reasonable expectation of the privacy of their own thoughts and that the use of such “brain scanners” by government agents does not constitute a search for the purposes of the Fourth Amendment. Fanciful? Yes. But possible? Yes. And scary? Definitely.