You’re running a restaurant — or maybe a mosque or an abortion clinic. Union members stand on a public sidewalk outside the restaurant and project light onto your wall that causes a message to appear on your wall: It says the restaurant got cited for health code violations. Or it says “this business hires scabs.” Or anti-Islam protesters project a Muhammad cartoon on the wall, or antiabortion protesters project an image of an aborted fetus. Can you stop this by going to court and getting an injunction, on the theory that the projection onto what is, after all, your wall is a trespass?

This issue has come up in at least several recent cases, all involving union speech — but it could equally involve other kinds of protests. The only one I’ve seen that has yielded written opinions is Int’l Union of Painters & Allied Trades Dist. Council 15 Local 159 v. Great Wash Park, LLC, 2016 WL 4165919 (Nev. Ct. App. July 29). And one of the opinions is very interesting indeed.

1. The opinion for the court is brief. It notes that different states adhere to one of two approaches: Under the traditional rule, “a trespass only occurs ‘where the invasion of land occurs through a physical, tangible object.’ ” “Tangible” here means more than microscopic; smells wafting from a pig farm, for instance, are borne by physical objects, but they aren’t trespass. Under the modern rule, “a trespass may also occur when intangible matter, such as particles emanating from a manufacturing plant, cause actual and/or substantial damage to the [property].”

Nevada precedents hadn’t resolved which theory applies, but there was no need to decide, the majority concluded, “because Local 159 did not commit trespass using either theory. Jurisdictions that adhere to either doctrine have stated that light is intangible. Because light is intangible, Local 159 did not commit trespass under the traditional theory. And because the light did not cause damage to GWP’s building, Local 159 did not commit trespass under the modern theory. … Because we conclude Local 159’s actions cannot constitute a trespass, the district court abused its discretion in issuing the injunction.”

The court rejected the union’s arguments that the injunction violated the First Amendment or was preempted by federal labor law. If the Nevada Legislature wanted to bar projecting images onto a wall, it could do so — but the common law of trespass did not impose such a prohibition, the court’s opinion held.

2. Judge Jerome Tao, though, wrote a much longer concurring opinion (in addition to joining the court’s opinion) and one that strikes me as very interesting and thoughtful. First, he discussed why this case might be harder than the court’s opinion suggests:

Virtually all of the “light trespass” cases cited by the parties, and in the court’s order, concern the potential trespassory effects of “ambient” light, by which I mean light intended to serve a legitimate ulterior purpose on a nearby property but which incidentally happens to leak or diffuse onto the claimant’s property; common examples of this include construction lighting or light reflecting off the screen of a drive-in movie theater.

In contrast, this case involves something arguably different: a beam of light specifically and intentionally directed at the Respondents’ property and nowhere else that served no purpose other than to intentionally light up the Respondents’ building the way the Union wanted.

Does this distinction make a difference? It seems to me that it possibly could, and if so then we are presented with a question of first impression, as almost all of the existing case law relates to ambient lighting….

Before the district court below [and in their briefing], the Respondents argued … that by projecting a text-based light image onto the Respondents’ wall, the Union interfered with the Respondents’ property-based right to instead put their own message on that wall, or have no message there at all. Had this argument been vigorously re-asserted before us, then we would have to squarely confront it.

But during oral argument the Respondents appeared to shift away from this argument. When asked whether what made the light image projection objectionable was that it was in the form of readable text, counsel responded that whether the image was readable or not was not the problem; the problem was that the light image altered the appearance of the property, and the property owner possesses the right to control the appearance of the property at all times.

Whether they intended it or not, by identifying the root of the problem as the effect of the lighting upon the appearance of the property, the Respondents have rendered irrelevant the distinction between whether the light invasion resulted from ambient lighting or focused lighting, or whether it contained text or was merely color. If the argument is that the projected light image interfered with the Respondents’ right to place their own message in the same place, then the interference could be accomplished just as easily with a monochromatic beam as with a textual light image. Furthermore, the question of whether light alters the appearance of property seems to me to have nothing to do with whether that light was ambient in nature or individually directed and focused at the property; if of sufficient intensity, both could affect the appearance of the property in the same way.

To analogize to a conventional trespass, a trespass committed by a person walking onto prohibited land would be no less a trespass if that person also happened to invade other nearby properties as well during his travels. Similarly, a pedestrian’s physical presence on the land constitutes a trespass regardless of whether he was there as part of an exercise routine utterly lacking a message, or whether he was there to make a point about something. Whether that person also trespassed onto other properties along the way, and whether his trespass was with, or free of, communicative purpose, are fundamentally irrelevant to whether a trespass occurred.

And that is the fundamental difference between an invasion by ambient lighting or focused lighting: whether the lighting went into many different directions and lit other properties in addition to this one with no communicative purpose, or whether it went only in one direction and lit only this property to convey a message.

By conceding that the problem was the effect that the light beam had on the appearance of the property — and not either the nature of the beam itself or the message it conveyed — the Respondents have made irrelevant the origin of the light beam, the direction of its projection, and the intent of party projecting it. Thus, the question of whether it matters that the light was only ambient lighting or rather was purposefully directed at the property is no longer at issue in this appeal. [Footnote moved: This could possibly be because analyzing the light projection based upon the message it contained might implicate questions relating to speech under the First Amendment or to federal pre-emption under the National Labor Relations Act. [EV adds: Note, though, that Tao joined the court’s opinion, which concluded that the First Amendment and federal labor law preemption claims should be rejected.]

Therefore, because we generally limit ourselves to answering only the question asked, I do not interpret our order here as addressing the question, which we necessarily leave unresolved, of whether it might make a difference in other cases for purpose of trespass law that the light at issue was not incidental leakage but rather was intentionally and specifically beamed at the affected property and served no other purpose than to light the Respondents’ property with a readable message.

3. Despite that, Tao concluded, the trespass issue — though close — should be resolved against a finding of trespass:

Even if we considered the nature of the beam itself (as argued in the briefing), rather than its effect on the appearance of the property (as argued orally), I am not sure the district court injunction could stand.

The Respondents argue that the beam of light itself is, by definition, a “tangible” thing that can “invade” real property. This argument derives from the language commonly used by various courts attempting to define the tort of trespass. According to the Respondents, light is a physical thing that can invade and therefore trespass onto property; according to the Union, it is not. Tracking the traditional judicial language, my colleagues conclude that the light projection at issue here did not constitute a tangible property invasion, and I agree.

But what does it really mean to say that something is “tangible” or amounted to a “physical” invasion? The Respondents do not allege that their property was physically harmed or damaged in any way; that their access to the property was impeded or obstructed by the Union’s activities; or that the Union attempted to possess or appropriate any portion of the property in any way, at least in the traditional sense of physically occupying space that belonged exclusively to the Respondents by virtue of their ownership of the land under the law of real property.

Rather, the argument made here is that the light projection constituted a trespass because light is composed of “particles” (according to the Encyclopedia Britannica, which the Respondents cite in their brief), and those particles are tangible and therefore capable of physically intruding across the Respondents’ property line. But whether something is “tangible” or not does not seem to me to be a proper or clear legal test, at least not one that can be readily understood and applied to a wide range of facts.

Instead, the argument strikes me as a syllogism based upon superficial pseudo-science, and I am not sure that the outcome of this case ought to be governed by this kind of approach.

As an initial observation, the science relied upon by the Respondents appears to be wrong, or at least incomplete. If one really wants to get into the physics of the question, light has the properties of both a wave and a particle. Scientifically speaking, light sometimes has the qualities of a particle and sometimes has the qualities of a wave, and, to make things even more complicated, it can have both qualities at the same time. So the scientific answer to whether light is a particle or a wave is that it is both; therefore, following the Respondents’ syllogism, sometimes light is arguably physical and sometimes it is clearly not. If this is our inquiry, then we are dealing with nothing more than an exercise in subjectivity, something akin to a Rorschach ink blot in which any judge can find a trespass, or not, depending on his or her personal predilections because both conclusions would be supported by the underlying science of the matter. But as a method of legal analysis, that gets us nowhere fast.

More fundamentally, technical merit aside, scientific analysis and legal analysis are two different modes of inquiry designed to accomplish very different goals. In science, data-based objective truth is all that matters. In law, courts care about the “truth” in the sense of achieving a just (or “right”) result in a particular case; but they also care about other things and can sometimes sacrifice individual truth in order to achieve other important policy goals, such as making the law predictable, consistent, stable, and clear even if not well-matched to the facts of every individual case.

Consequently, even if it were unequivocally true that a quantum physicist would think of light as formed of particles, that conclusion alone should not govern whether we should find a trespass here as a matter of legal analysis and underlying public policy. There is a place for science in drafting and interpreting the rules that govern human conduct, but determining what scientists may think about a matter in legal dispute is not the ultimate goal of what courts do.

Properly framed, I think the question before us is not whether light is tangible or not, but instead: what legal right inherent in property ownership does the light projection supposedly violate? …

Fundamentally, the right to own property is the right to exclude others from entering, using, or possessing it. In a real sense, whenever property is bought or sold, what has really been purchased is the right to sue someone in court for trespass for entering, using, or possessing the property without the owner’s permission.

The Nevada Supreme Court has said that a trespass occurs when a property right has been physically invaded. Alternatively, the tort has also been described more broadly as protecting against “[a]ny misuse of the land or deviation from the intended use of the land.”

But these are relatively generic phrases, and it is not entirely clear how they can be applied to the particular facts at hand…. Fundamentally, the problem here is that we are confronted with a clash between very old law and evolving new technology. Trespass is one of the oldest torts known to Anglo-American jurisprudence, dating as far back as twelfth-century England. But back then, even the most advanced thinkers of the day were not aware of such things as atoms, electrons, or photons ….; it would be another two centuries before Galileo proved that the earth revolved around the sun, a revelation so antithetical to prevailing thought that he was burned at the stake for suggesting it.

It should come as no surprise, therefore, that the tort of trespass was originally limited to physical invasions of property by people or objects composed entirely of matter; as far as anyone knew, there was nothing else that existed in the universe that could invade anything. In an era lit by wax candles, and then whale-oil lamps, and then kerosene, there was not much that one could do to another’s property with light.

But nowadays light can be so many more things and can be used in so many more ways; searchlights, lasers, and light projectors of the kind involved in this case are now commonplace. The inquiry here is whether the bundle of rights traditionally protected by the ancient tort of trespass should be read to include the right to stop the newly-developed light projection used here.

4. And the answer to that inquiry, Tao concluded, is that the question should be treated under the tort of nuisance rather than the tort of trespass:

The torts of trespass and nuisance are closely related, so much so that some courts have observed that expanding the tort of trespass to cover such things as light, gas, or odors effectively blurs the two torts together and makes them one. The traditional common-law view was that property injury caused by such things as light, gas, sound, smoke, odors, or vibrations might constitute an actionable nuisance under the right circumstances, but could not support a cause of action in trespass. On the other hand, a substantial minority of modern cases have held that light invasions can constitute a trespass so long as substantial harm results to the property. But, speaking generally, most commentators and the majority of courts consider light invasions to be better suited for the law of nuisance rather than trespass.

I agree with the view that light invasions — at least of the kind at issue here– are better suited to be addressed by the law of nuisance than the law of trespass. The fundamental conceptual difference between a trespass and a nuisance is that trespass is the right to exclude something absolutely, while nuisance is the right to exclude something that might have to be tolerated in small quantities but may become the subject of judicial relief when it becomes excessive and unreasonable even in an urban environment. Compare Crook v. Sheehan Enters Inc., 740 S.W.2d 333, 335 (Mo.App. E.D.1987) (“Trespass is the unauthorized entry by a person upon the land of another, regardless of the degree of force used, even if no damage is done, or the injury is slight.”) and Kitterman v. Simrall, 924 S.W.2d 872, 878 (Mo.App. W.D.1996) (noting that liability for trespass “exists whether or not done in good faith and with reasonable care, in ignorance, or under mistake of law or fact”) with Sowers v. Forest Hills Subdivision, 294 P.3d 427, 431 (Nev. 2013) (nuisance “may arise from a lawful activity conducted in an unreasonable and improper manner” and in evaluating whether an activity constitutes a nuisance, “it is necessary to balance the competing interests of the landowners, using a commonsense approach.”). See generally Restatement (Second) of Torts, § 821D (Am. Law Inst. 1979) (trespass is an interference with a property owner’s right to exclusive possession of a property, while a nuisance is an interference with the owner’s use or enjoyment of the property).

Thus, the tort of nuisance involves a balancing of competing interests with an eye toward ascertaining the reasonableness of the intrusion, while the tort of trespass is absolute and involves no such balancing. What this means for this case is that, by claiming a trespass to have occurred, the Respondents are seeking an absolute bar against the invasion of projected light, without any inquiry whatsoever into whether the intensity, duration, or other qualities of the projection were unreasonable or excessive. Indeed, the Respondents specifically argue in their brief that

The fact that [the Union] only projected images for a limited duration of time … does not absolve it of trespass liability…. [T]he question of trespass is not one of scope or degree; rather any interference … no matter its manner or duration — is actionable.

But while it is true that manner and duration do not matter when applied to traditional trespasses committed by people or super-atomic objects, when applied to light, the Respondents’ argument goes too far and takes the law of trespass to a place it was never meant to go….

Human beings see things only when light is either projected by, or reflects off of, an object and enters the retina; without light, nothing is visible and the world would be dark. Thus, a property such as the Respondent’s building can only be seen at all if some source emits enough light to reflect off of the building with sufficient intensity to trigger the nerves within the eye of a human observer. During the daytime, this source can be natural rather than artificial (the sun), but, at night, artificially created and projected light (that is, excluding light from the sun, the moon, and the stars) might be necessary to light the building or else it might be invisible.

Every property located in a densely populated urban area like Las Vegas is continually bombarded by multiple artificial light sources, including such assorted things as street lamps, commercial neon signs, neighboring porch lights, automobile headlights, helicopter searchlights, the ambient glow cast by the Las Vegas Strip over the horizon, and the like, even such barely visible things as pedestrian cell phone screens or cigarette embers. Everything that a human being can see from the property is, technically speaking, a light wave crossing the property line and invading the property.

All of these lights affect the appearance of the property with varying intensity and duration, some brief and barely perceptible, and some with great intensity for long periods of time. If the Respondents are correct and neither intensity nor duration are relevant to whether a trespass has occurred, then all can be the subject of judicial relief no matter how transient or barely perceptible the effect on a property. If the Respondents’ argument is correct, then a court could enjoin every light visible from the property anywhere in the city — could order it all turned off — under the rubric of protecting a property right.

[Footnote: Indeed, the Respondents light their own property with an array of lights. Surely they do not believe that the light they project stops at their property line and doesn’t intrude into neighboring properties; quite to the contrary, the very point of their lighting is to make the property visible from far away so that customers can find it at night. So, if the Respondents are correct that projected light constitutes a trespass when it crosses a property line, then the Respondents are themselves trespassing onto every neighboring property from which their property is visible.]

Ultimately, when the question is properly framed, the answer strikes me as quite simple: I do not think that the absolute right to block artificial light emanating from somewhere off of the property — without any inquiry into its intensity, duration, reasonableness or unreasonableness — should be included within the “bundle of rights” that one acquires when purchasing a parcel of land in a densely populated urban center like Las Vegas. Trespass law does not convey the right to live in a black hole. I would therefore conclude that the light that was projected in this case does not constitute a violation of the law of trespass. The injunction below was based upon the wrong tort.

On the other hand, simply because a property owner does not have the right to exclude all light emanating onto a property under trespass law does not mean that one must tolerate every kind of light that is beamed onto the property no matter how excessive or unreasonable it may be. In some cases, projecting artificial light onto someone else’s property might constitute an actionable private nuisance. The district court’s order contains no factual findings regarding whether such a nuisance occurred in this case, and so that question is not before us.

I therefore agree with my colleagues, for all of the reasons set forth in the court’s order but also for the additional reasons outlined herein, that the injunction is void and a reversal is in order.

5. Finally, a practical question, but perhaps one with some legal significance: Wouldn’t it be relatively cheap to hire someone who’ll also stand on the sidewalk and project some light over wherever the protesters are projecting it? That wouldn’t make the wall look pretty, but it should be enough to make the original display illegible. If this is indeed relatively easy (and I may be mistaken on that), should that matter to the legal analysis?