What is a Reasonable Expectation of Privacy in the Surveillance Context?
While infringement of a reasonable expectation of privacy is decided on a case-by-case basis, courts are especially likely to base their decisions on whether the surveilled things or actions were held out to public view in any way and on the level of intrusiveness of the surveillance technology.
Video Surveillance of Things in Public View: Courts have routinely held that individuals have no reasonable expectation of privacy to things or actions held out to public view, regardless of the individual’s location. The Supreme Court has stated that “what a person knowingly exposes to the public, even in his home or office, is not a subject of Fourth Amendment protection.” This includes the actions of a person on a public street, things inside a home that are still viewable through an open door or window, and even things on private property that the property owner has taken some measures to conceal but that are still viewable from a lawful vantage point.
In California v. Ciraolo, the Court determined that non-enhanced aerial photography of marijuana plants on Ciraolo’s private property did not violate the Fourth Amendment, even though he had built 10-foot-high fences to prevent passers-by from viewing his property. Visibility from any conceivable angle, including the airspace above, puts an object in public view. The Court stated: “The Fourth Amendment protection of the home has never been extended to require law enforcement officers to shield their eyes when passing by a home on public thoroughfares. Nor does the mere fact that an individual has taken measures to restrict some views of his activities preclude an officer’s observations from a public vantage point where he has a right to be and which renders the activities clearly visible.” Simply put, if it is visible with the naked eye from a public vantage point, then it is not protected by the Fourth Amendment.
Using Enhancing Technology in the Surveillance of Public Areas: No court has found enhanced video surveillance of a public area to be a search under the Fourth Amendment, but dicta by the Supreme Court leave open the possibility.
Despite the general rule that there is no reasonable expectation of privacy to things or actions held out to public view, the Court has clearly stated that “people are not shorn of all Fourth Amendment protection when they step from their homes onto the public sidewalks.” Katz v. United States established that under the right circumstances, an individual may be able to claim a reasonable expectation of privacy even when in a public area. In Katz, the Court found that warrantless interception of a conversation in a public telephone booth violated the Fourth Amendment. Katz had manifested an intent to keep his conversation private by entering the phone booth and closing the door, and the Court determined that privacy within a public phone booth was something that society was prepared to accept as reasonable.
The Supreme Court has also recognized the possibility that surveillance with enhancing technology, when used in public areas, might infringe on a reasonable expectation of privacy. In United States v. Knotts, police officers used a beeper tracking device planted in a car to monitor the car’s movements. While “nothing in the Fourth Amendment prohibited the police from augmenting the sensory faculties bestowed upon them at birth with such enhancement as science and technology afforded them,” the Court’s decision rested on the fact that the enhancing technology (the beeper tracking device) was simply a “more effective means of observing what is already public.” The Court’s implication is that technology that allows the observation of things that are not in public view may run afoul of the Fourth Amendment. Similarly, in Dow Chemical Co. v. United States, the Court noted that certain levels of surveillance detail, such as zooming in on a finger to identify a class ring, may violate the Fourth Amendment, even in a non-home environment.
If it is possible for surveillance technology in public areas to violate the Fourth Amendment, how will we know when it does? What will that technology look like and how will the Supreme Court analyze the technology’s use? Only time will tell the answers to some of these questions, but based on the Supreme Court’s standard for privacy, the offending technology would need to be capable of observing something that an individual has sought to protect as private in a way that society is prepared to recognize as reasonable. The Supreme Court may determine that when a technology makes visible those things that would not otherwise be visible without physical intrusion, it may violate the Fourth Amendment. Still, this question would be decided on the facts of each case, and “not by extravagant generalizations” or merely the technology’s potential to invade privacy.
Troublesome Technologies on the Horizon
It is impossible to tell what types of surveillance technologies the future will bring, but there are already examples of technologies that may run into challenges under the Fourth Amendment. Included here are just two examples:
Backscatter X-Ray: Backscatter X-ray technology uses a narrow, low intensity X-ray beam scanned over the surface of a body or other object at high speed. The result is a detailed picture of the scanned individual’s body, displaying all items that the individual may be carrying on his/her person, even under clothing, or displaying the contents of the scanned object. The American Civil Liberties Union has referred to the technology as a “virtual strip search.” Backscatter X-ray technology is already in use at some airport security stations as an alternative to invasive pat-down searches, and at border terminals as a method of scanning the contents of cars and cargo containers.
The Fourth Amendment does not apply in the same manner in these high-security contexts, where there individuals have “consented” to such searches by virtue of choosing to fly in an airplane or crossing the border. As this technology develops, however, its migration to main street is becoming more apparent. The Z Backscatter Van from American Science and Engineering Inc., places a backscatter X-ray unit within an ordinary looking delivery van. The van can drive by cars and trucks to scan the contents of trunks and cargo holds, or, if parked by the side of a street, it can scan passing vehicles and pedestrians. AS&E is marketing the van as a tool for homeland security and “urban surveillance.”
Pairing backscatter X-ray technology with a public video surveillance system would allow a view of individuals not only as they appear to the public on a street, but also of every item that the individual may be carrying under their clothing. Backscatter X-ray may be just the type of technology that the Court in Knotts pondered that goes beyond merely augmenting vision to seeing those things that are not otherwise visible to the public. If the area beneath an individual’s clothes is one that society is prepared to recognize as private, which seems likely, then this may be a Fourth Amendment violation.
Heart Sensing Radar: On December 15, 2008, the Department of Homeland Security issued a Privacy Impact Assessment for the Future Attribute Screening Technology (FAST) Project. The FAST Project will test technology linking video surveillance with a remote sensor that can measure the heart rate and respiration patterns of a subject from a distance and without physical contact. The technology could be used to remotely identify the physiological status of an individual and help determine whether that individual may be about to commit a crime or cause a disturbance, based on, for example, a racing heart rate.
Heart Sensing Radar is already being marketed by private companies. On January 9, 2009, Kai Sensors Inc., issued a news release touting a recent partnership that will help bring the technology to market for use in “law enforcement missions” and “intelligence gathering.” While no cities have disclosed using Heart Sensing Radar in connection with public video surveillance yet, the possibility is clearly in the foreseeable future.
Heart Sensing Radar technology gives a clear example of the types of questions Courts will be forced to consider in the near future with respect to the Fourth Amendment. Certainly an individual does not have a reasonable expectation of privacy as to their stressed or excited physical appearance, but what about as to the movements of their bodily organs hidden from public view? Such a question was unfathomable even a year ago.
The proliferation of public video surveillance systems and new surveillance technologies provide exciting potential in the world of public safety and law enforcement. However, new technologies also raise new legal questions. The longstanding Supreme Court standard that individuals have no reasonable expectation of privacy to things held out to public view becomes more complicated as new surveillance equipment has the ability to see more and more. Cities may be wise to adopt public video surveillance systems, but they should proceed with caution to ensure that their systems do not have the potential to violate the Fourth Amendment.