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  • J.D. LeFrere

Revisiting Kyllo v. United States’ publicly available technology test and it’s implication on drone

Updated: Oct 20, 2023

In 2001, the United States Supreme Court, in Kyllo v. United States, decreed that an important facet through which to determine whether a Fourth Amendment violation had occurred was that of the availability of technology. Justice Scalia famously stated in the Court’s opinion that the “[use of] a device that is not publicly available to see details of a private home that would be undiscoverable without physically entering the home constitutes a Fourth Amendment search.” This standard, however, is vague and, considering the rapid pace of which technology is advancing daily, troublesome to say the least. Despite the Court adding a technology prong to the Katz reasonable expectation of privacy standard, the reigning test for a Fourth Amendment violation, they continued to abstain from defining what constituted “technology that is not in general public use.” Does price and ease of access when obtaining a specific piece of technology consider it “publicly available” for Fourth Amendment purposes? If so, does a publicly available piece of technology shift the burden to individual citizens to argue why a specific activity is entitled a reasonable expectation of privacy? And if the technology is publicly available per Kyllo’s standard, does it then allow law enforcement to utilize said technology without a warrant? There is no shortage of questions when seeking to rectify the Kyllo standard with countless technological innovations that permeate our daily lives today. Perhaps one of the most looming and concerning though affects the increasing usage of drone technology’s by law enforcement for mass surveillance purposes.

In 2014, in response to the ever-growing usage of drones in the country, Congress required the FAA to create regulations pertaining to the public use of drones. In 2015, the FAA required that any private citizen seeking to operate a drone weighing more than half a pound and less than fifty five pounds to register them, and any drones weighing over fifty five pounds were required to be registered with the FAA’s aircraft registry. To date, there are nearly two million registered drones in the FAA’s registry. This is a significant amount of usage and is poised to continue to grow exponentially given that the cost of a camera-equipped drone ranges anywhere from $300 to $1000, or just about the cost of our cellphones these days. Certainly, it is not an unreasonable inference to say that drone technology is, to an extent, publicly available given these statistics.

If we accept the prevailing mentality that drone technology is publicly available today, I propose a hypothetical situation. Imagine a scenario where law enforcement and/or intelligence agencies continue to expand their usage of drone technology to surveil the public. Prior to Kyllo, in California v. Ciraolo when the Court decided that police usage of a helicopter over the curtilage of a home to glean whether the defendant was growing marijuana was not a Fourth Amendment violation because the area surveilled was exposed to the public above. The Court reasoned that because the helicopter was in public airspace at a one thousand foot elevation, coupled with the fact that the defendant failed to obstruct his plants from public aerial view, meant his reasonable expectation of privacy was negated. When applied in conjunction with Kyllo regarding mass public surveillance, the government would not be required to obtain a warrant to conduct mass surveillance of American citizens so long as they kept said surveillance to public areas, to include public airspace. What arises is a recipe that will wreak havoc on a citizen’s Fourth Amendment privacy rights.

In response to these concerns, a new theory has emerged regarding how best to address the growing privacy degradation posed by emerging technologies. The Mosaic Theory, established in the 2010 case of United States v. Maynard, sets forth the idea that “an accumulation of actions by law enforcement, none of which individually intrude upon a reasonable expectation of privacy, may together constitute a Fourth Amendment search.” To an extent, the Court has already ruled that aggregated data collection by law enforcement required a warrant by way of the Carpenter v. United States decision. Yet, this decision only applied to cell tower data, further establishing the Court’s preference for deciding technology related privacy issues on a case-by-case basis. This, unfortunately, leaves gaping legislative holes that have the potential to be exploited by the government. To date, there is no definitive time period during which a person can be surveilled without a warrant, nor has the Court addressed the omnipresent usage of surveillance in public spaces to the extent that it rectifies questions of bulk data collection. Instead, what has emerged is a world in which technology outpaced our awareness of privacy deterioration. Ultimately, this has left us as individual citizens scrambling to understand and enforce Fourth Amendment privacy rights in our technology-saturated world. Further, as technology continues to permeate our homes as well, the notion that Fourth Amendment protection is strongest within our homes, too, becomes opaque at best when considered within a framework of recent case law.

Under a mosaic theory approach, such issues as ongoing surveillance in public spaces and the resulting bulk data collection could provide the means through which we as individual citizens begin to regain Fourth Amendment ground while simultaneously enabling us to truly define a reasonable expectation of privacy in the modern digital age.


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