The use of self-defense against drones has become a hot topic, especially in the wake of the case of a New Jersey man who shot down a drone that was flying over a neighbor’s property.

In a guest column at the ever-valuable Volokh Conspiracy blog, law professor A. Michael Froomkin and his research assistant, Zak Colangelo, present their thoughts on the law of self-defense against drones. They offer a great deal of food for thought, and we recommend reading the whole thing. But while we agree with some of their arguments, we have reservations about others.

Froomkin and Colangelo begin with a general observation about the applicability of self-help doctrines to robots:

[W]hen a person fears for her safety, property, or privacy, the same self-help doctrines that govern other issues should govern a person’s use of self-help against a robot, whether that robot is operating on land, air, or sea. That is, an individual threatened with harm should be able to employ countermeasures that are reasonable in proportion to the harm threatened. The rule shouldn’t be different just because a robot poses the threat. Thus, as a general matter — but subject to some pretty important exceptions — a person who reasonably fears harm from a robot has a right to act to prevent that harm, up to and even in some — but far from all — cases shooting it down.

It is important to note, they point out, that the law treats robots as property. Because the law places a greater value on human life than it does on property, “[a]cts of self-defense that would be unreasonable when threatened by a human will in many cases be reasonable — in an otherwise similar situation — in response to threats from a mere chattel.” However, “[t]he toughest question is the scope of permissible self-help when individuals fear for their privacy rather than for their safety or property….” (emphasis added).

Froomkin and Colangelo point out that, whereas a threat to one’s property is easier to quantify, a threat to one’s privacy is not:

A trespassing, spying drone can do a lot of damage, but privacy harms are hard to monetize, especially ex ante.* That means it is hard to weigh the potential damage against the harm that the self-helper risks doing to the offending chattel. Not only is privacy is hard to value in general, but in this case the victim cannot know in advance how the operator of the drone intends to use the photos, hacked wifi, or whatever the drone may be collecting.

In light of this uncertainty piled on difficult valuation, we argue that the scope of permissible self-help in defending one’s privacy should be quite broad — else privacy will inevitably lack the protection it deserves. There is exigency in that resort to legally administered remedies would be impracticable — the drone will be long gone — and worse, the harm caused by a drone that escapes with intrusive recordings can be substantial and hard to remedy after the fact. Further, it is common for new technology to be seen — reasonably — as risky and dangerous, and until proven otherwise drones are no exception. At least initially, violent self-help will seem, and often may be, reasonable even when the privacy threat is not great, or even extant, at least when the risks of collateral damage are small.

While recognizing that those who operate drones on the periphery of one’s property probably have some valid First Amendment claims, Froomkin and Colangelo “understand why people would be concerned to learn that drones might someday aim telephoto lenses into their bedrooms from the sky.”

Because an average person is likely to be unable to immediately assess a drone’s threat to his or her privacy, they argue that “[t]ort law is likely to be solicitous of the property-owner’s need to make quick decisions under uncertainty. That solicitude will not, however, extend to actions that presented a reasonable risk of danger to third parties, such as shooting into the air in populated areas….” (emphasis added).

We whole-heartedly agree with the latter point regarding actions that present a danger to others, but think that their underlying assumptions are flawed. First, keep in mind that, as we have noted here, it is highly improbable that a civilian drone operating in Class G airspace is going to have any meaningful “spying” capabilities. It might be noisy and bothersome, but a drone is not very effective as a “peeping Tom” device (unless you’re sunbathing nude in your backyard or on your roof, in which case your claim to a reasonable expectation of privacy is probably dubious, at best).

Froomkin and Colangelo suggest that the uncertainty over drone capabilities could be resolved by, first, instituting a blanket ban on weaponized drones in the U.S. We think this is a reasonable suggestion. But, then again, how have blanket bans on weapons worked out in the past? The track record is not so great.

In any event, a small drone is unlikely to be a useful weapons platform. As anyone who has fired a gun can attest, the kickback from discharging a firearm would be just as likely to send a small drone tumbling out of the sky as it would be for the drone to hit its intended target.

Next, they propose that

all mobile robots should be required to carry warning markings, lights, and the equivalent of a Vehicle Identification Number (VIN) that would be recorded in a state or national registry…. Although far from perfect, these notices would be calibrated not just to warn of the drone’s presence, but also to say something about its capabilities, such as whether it carries a camera, and whether it is capable of capturing sounds or wifi or other information.

They further suggest that “[s]etting up a licensing regime and national or state-based registries would help connect a malfeasant robot to its owner or user, but no single system is likely to work in all circumstances.”

Froomkin and Colangelo seem to concede that their regime might well be unworkable, due in part to the problem of “cheating.” But we think that their proposal is far too complex, and relies far too much on unworkable regulatory regimes that will create more problems than they are likely to solve.

We propose a much simpler approach. First, we are persuaded that civilian “microdrones” should be regulated as consumer products, like cell phones and lawn mowers. We discussed that in a post on August 30, 2014. Off-the-shelf, consumer product regulations would solve many of the problems mentioned by Froomkin and Colangelo. For example, microdrones could be required to have built-in limitations on range and height. Naturally, they could be prohibited from having any sort of weapons capability.

Regulating microdrones as consumer products would also dispense with the need for a licensing regime. Model aircraft have been operated for generations without the need for mandatory licensing regulations. Maintaining a reasonable line-of-sight range limit for consumer model aircraft would more than adequately address concerns about hazards to public safety.

This sort of approach would remove much of the ambiguity concerning the capabilities of civilian microdrones. To the extent that any ambiguities might still exist, we think that the rules for using self-help against perceived threats from drones should be made abundantly clear.

We first note that we are adamant supporters of the right of self-defense as a fundamental human right. But with that comes an abiding respect for firearms safety and for the property rights of others.  Absent the sort of threat that would give rise to a justifiable use of deadly force under applicable state law, we would never advocate discharging a firearm in a heavily populated area. Froomkin and Colangelo seem to agree.

State legislatures could, if they wished, enact laws clarifying the circumstances in which a person may presume a threat of death or serious bodily harm from a drone, much like some state laws allow one to presume such a threat when an intruder invades one’s home or automobile. But we do not think that extending such a presumption to model aircraft would be a good idea.

The entire discussion might also be academic.

The FAA claims the authority to regulate or even prohibit the use of any flying object operated outdoors, no matter the altitude or distance from an airport, etc. If the FAA’s sweeping claim of jurisdiction is correct, then questions of federal/state preemption are going to necessarily come into play.

Current federal law prohibits the shooting down of any aircraft. Many small drones are already being regulated as “aircraft” by the FAA. Just consider the recent spate of 333 exemptions to the FAA’s “ban” on commercial drones. If one were to shoot down a drone being operated under such an exemption, it would be hard to argue that one had not just committed a federal crime.

But more than that, the FAA claims that the definition of “aircraft” includes model aircraft. Thus, according to the FAA, shooting down a model aircraft should be a federal crime. Until the FAA provides clarity on that, any discussion of whether a drone can be shot down by a civilian, under any circumstances, is unlikely to be useful.

*Lawyer-ese for “before the event.”