Would Flying a Drone "Outside of Navigable Airspace" be a Fourth Amendment Search?

John Burkoff has recently posted an article to SSRN on whether the Fourth Amendment's protection from unreasonable searches can limit the government's use of drones for law enforcement purposes. After surveying the history and development of Fourth Amendment jurisprudence, he concludes:

[L]aw enforcement officers cannot, in any event, use drones – as a matter of federal constitutional law – when they: (1) are flown outside of navigable airspace; (2) create undue noise, wind, dust, or threat of injury; or (3) obtain any information in an effectively physically intrusive manner from a constitutionally protected area.

I've blogged previously about the extent of Fourth Amendment protection against aerial surveillance of one's home and person. To briefly summarize, the government may use a plane or helicopter to conduct surveillance of one's home or person as long as the government is flying within commonly-navigated airspace. (See Florida v. Riley).

Already, there is a problem with Burkoff's claim that "navigable airspace" limits where law enforcement agencies can conduct aerial surveillance. While the plurality in Riley stated that Federal Aviation Administration (FAA) regulations governed where law enforcement helicopters could fly, Justice O'Connor's concurrence took the narrower approach that police needed to fly their aircraft in locations and at heights where that type of aircraft was commonly used. The test, therefore, is not whether the airspace is "navigable," but rather, whether the airspace is "navigated."

This test is difficult to apply to government drone use. The government may not use planes or helicopters to conduct surveillance at certain heights (say, below the Riley height of 400 feet), because those types of aircraft are not commonly flown below those heights. But drones are not subject to the same limitations as aircraft. In fact, the FAA has stated that drones may be used by hobbyists as long as they are flown below 400 feet. The FAA also states that drones are not to be flown above heavily populated areas, which may be a point in favor of those who argue that the Fourth Amendment limits government drone use. Perhaps these restrictive FAA guidelines can lead to stronger Fourth Amendment restrictions government drone use compared to Fourth Amendment restrictions on the use of planes and helicopters.

Drone advocates, however, argue that these regulations are simply advisements that do not carry the force of law, since the FAA has not yet drafted explicit rules for the use of drones. Hobbyists, after all, frequently use drones for photography and shooting video over populated areas, and this activity has not been prosecuted by FAA officials.

In the absence of clear restrictions, frequent and widespread hobbyist drone use may mean that the Fourth Amendment restricts government drone use even less than it restricts alternate means of aerial surveillance. Regulations governing helicopters and airplanes have the force of law and are consistently followed, which means that there are clear boundaries governing where law enforcement can and cannot fly these aircraft. But the legal uncertainty surrounding regulations of drone flight means that it is not at all clear where and how drones are commonly used.

This uncertainty could lead courts to conclude that drones are not commonly flown above houses or streets, and therefore could allow for greater Fourth Amendment protection against government drone use. But it could also lead courts to find that hobbyist drones are commonly flown at low heights over houses, streets, and parks, meaning that government drones could be flown in the same manner without implicating the Fourth Amendment.

In light of this uncertainty, it may be overly hasty to conclude that the Fourth Amendment prohibits government drone use outside of "navigable" airspace. Even if that conclusion is true, the boundaries of this navigable airspace are not at all clear.

All of this discussion illustrates only one of the difficult issues that courts would need to answer in the event that government drone use is challenged on Fourth Amendment grounds. I argue elsewhere that legislation is a better avenue for addressing these complicated questions. But in states without drone laws, whether it is because of legislatures' resistance or executive vetoes, courts may not have long until they are required to rule on these issues.