State Bar of Texas

Texas Bar Journal • November 2023

Written by Ronald J. Sievert

As 2024 approaches, many of us understand that in the next few years we will be confronted with flights by and questions about drones, also known as unmanned aerial vehicles, or UAVs. Those of us involved in law enforcement, intelligence, scientific exploration, and research want to use them. At the same time, those of us who are also concerned about privacy do not want them flying over our land, houses, or private corporate property. This naturally leads to an examination of our legal rights and questions that have not yet been answered by the U.S. Supreme Court.

We do have some guidance in prior cases decided by the court. In the 1980s, there were numerous legal challenges when law enforcement and regulators began to use low flying airplanes and helicopters to find those growing marijuana or violating environmental laws. The key issue was whether the government action was a “search” under the Fourth Amendment which, in essence, meant determining if the complaining party had a “reasonable expectation of privacy” in the property that was being observed from the sky. If there was such an expectation of privacy, then the government could not act without a court authorized warrant based on probable cause. In California v. Ciraolo,¹ the Supreme Court held that law enforcement could take pictures of a fenced-in backyard from a plane flying at 1,000 feet without a warrant. In Florida v. Riley,² the court also held that a police helicopter hovering at 400 feet in compliance with Federal Aviation Administration, or FAA, regulations could take photographs through the opening of a greenhouse within a home’s private curtilage. Although these decisions were close calls, the bottom line was that the majority of the court reasoned that we all know that planes and helicopters fly overhead and therefore those who objected did not have a “reasonable expectation of privacy.” Court warrants based on probable cause were not needed.

Another element was added to the equation of court review in Dow Chemical v. U.S.³ In that case, the Supreme Court held that the Environmental Protection Agency, or EPA, did not need a warrant to employ a conventional and commonly available “mapping camera” to photograph a closed industrial facility from higher altitudes in navigable air space. But the court noted that it would have prohibited the EPA’s warrantless action if the camera had been “highly sophisticated surveillance equipment not generally available to the public.” That is, an extremely technical camera would have violated the corporation’s reasonable expectation of privacy. The importance of technology was emphasized by the court in Kyllo v. U.S.⁴ In Kyllo, the Drug Enforcement Administration, or DEA, suspected an individual was growing large amounts of marijuana inside his home. They took photographs using a special infrared thermal imaging camera that revealed abnormal heat signatures in the home consistent with growing and providing internal heat to numerous plants. Although the agents were on a public street when they used the device and the outside of the house could be observed by all those passing by, the court held that use of this special camera violated the homeowner’s “reasonable expectation of privacy.”

These cases provide some insight into the court’s thinking but they do not answer some of the key questions about today’s drones. A helicopter can fly over your house at 400 feet but what about a drone at an even lower altitude? Does it make a difference if the drone is operated by your nosy neighbor or another private party as opposed to the government in a criminal investigation? After all, the whole formulation of defending our “reasonable expectation of privacy” grew out of Fourth Amendment cases focused on protecting citizens against government criminal investigative action.

Part of the answer to these questions, I believe, can be found in the court’s opinion in a fascinating 1940s chicken farmer case.⁵ To quote directly from the court’s factual summary:

Respondents owned a dwelling and a chicken farm near a municipal airport. The safe path of glide to one of the runways of the airport passed directly over respondents’ property at 83 feet, which was 67 feet above the house, 63 feet above the barn and 18 feet above the highest tree. . . . Various military aircraft of the United States used the airport. They frequently came so close to respondents’ property that they barely missed the tops of trees, the noise was startling, and the glare from their landing lights lighted the place up brightly at night. This destroyed the use of the property as a chicken farm and caused loss of sleep, nervousness, and fright on the part of respondents.

The farmer sued the government for “trespass” on the grounds of the old common law doctrine that the landowner owns all the sky above their property “into the periphery of the universe.” Justice William O. Douglas, writing for the court, noted that this old doctrine had no place in the age of air travel because the air was now “a public highway.” But Justice Douglas noted that if the landowner was to have full enjoyment of his land, he must have control of the “immediate reaches of the enveloping atmosphere. Otherwise, buildings could not be erected, trees could not be planted and even fences could not be run.”⁶ In other words, the owner owns as much of the space above the land as he can use in connection with the land.

United States v. Causby thus applied civil law principles and ruled in favor of the landowner in a case that had nothing to do with government investigative actions or the Fourth Amendment’s reasonable expectation of privacy. Naturally my more aggressive students always ask if this means they can use a shotgun to shoot down an annoying neighbor’s drone. My response is that they should just be ready to show the case to their lawyer when they are hauled into court.

Finally, in Long Lake Township v. Maxon,⁷ a decision involving an actual drone was decided by a high-level court. In that case, the Michigan Supreme Court reviewed the complaints against drone flights asserted by Todd and Heather Maxon, who had been fined for consistently violating local zoning ordinances by keeping an excessive amount of junk cars and other trash on their property. Long Lake Township used a UAV flying within FAA regulations (less than 400 feet and line of sight with the operator) to photograph the property and demonstrate the zoning violations in a civil suit against the Maxons. The state Supreme Court held that the UAV violated the Maxon’s reasonable expectation of privacy, and the township needed to get a court warrant before using the vehicle. The opinion was not exactly based on altitude of the UAV but on developing technology. In the above cited airplane surveillance cases, the Supreme Court had noted that photographs might be prohibited if the camera was highly sophisticated. In Kyllo, the court suppressed the thermal imaging pictures taken from a public street because of the high level of technology utilized. A court might apply the same logic to a complaint against a sophisticated drone launched form a public street that observed a private backyard. Futhermore, in the 2018 case of Carpenter v. U.S.,⁸ the Supreme Court held that the government could not use accumulated cell site locator information, or CSLI, to convict a major criminal because, even though we all know the cell company has access to the information, “society’s expectation (of privacy) has been that law enforcement and others would not (and could not) secretly monitor” all of their physical movements for a long period of time. Drawing on these two cases, the Michigan court held that, because of the new technology, drone surveillance is “qualitatively different” than surveillance conducted by airplane or helicopter and was thus improper without a warrant based on probable cause.

There can be serious disagreement with the reasoning behind the majority court opinions in Long Lake Township. In a later opinion, the Michigan court decided that the exclusionary rule did not apply to civil fine cases, but even its basic holding relying upon Fourth Amendment “expectation of privacy” analysis can be questioned. In today’s world of ubiquitous aerial drones, it would be hard to say that drones are not in “general public use” as was the case with the thermal imaging device in Kyllo or the ability to access CSLI in Carpenter. Technology can evolve and becomes so dominant and prevalent that we have less traditional
“expectation[s] of privacy.” Texas did pass a statute⁹ prohibiting drones from flying low to “conduct surveillance on the individual or property captured in an image.” But, in addition to being vague, the statute has numerous exceptions for drones utilized for commercial purposes, by any government entity, and according to a recent federal district court ruling, by newsgathering organizations.¹⁰ It also must be remembered that constitutionally, the Fourth Amendment expectation of privacy test often does not apply to “open fields.”¹¹ It would appear that in the future, some complainants might have a better argument if they rely on the application of the ownership of the “enveloping atmosphere” test explained in the 1946 Causby chicken farmer case. That is, they might be able to legitimately protest an aircraft of any kind flying the equivalent of 67 feet above their house, 63 feet above the barn, or just 18 feet above nearby trees. ^TBJ

RONALD J. SIEVERT graduated from St. Bonaventure University and the University of Texas School of Law. He served as chief prosecutor in the Criminal District Court in Jefferson County, Texas, a division chief in the U.S. Attorney’s Office for the Eastern and Western Districts of Texas, and assistant director at the U.S. Department of Justice. He has taught national security law and international law for 20 years as an adjunct at the University of Texas School of Law and full time in the international affairs and national security graduate programs at the Bush School of Government and Public Service at Texas A&M University.