Exposure to the Public

Exposure to the Public

The privacy route to a search carries an internal limit, and that limit decides a large share of investigative cases. The word "search" is a legal term of art, so conduct a layperson would call searching, such as sifting through a person's garbage or observing a yard from an airplane, often is not a Fourth Amendment search at all.¹ The source of the limit is the opinion that created the privacy test. In Katz v. United States the Court said that the Fourth Amendment protects people, not places, and in the same passage it added that what a person knowingly exposes to the public, even in the person's own home or office, is not protected, while what a person seeks to preserve as private, even in an area accessible to the public, may be.²

This corollary is the public exposure rule, and it operates through both prongs of the privacy test. A person who leaves something open to view has displayed no actual expectation of privacy in it, and even a person who privately hoped that no one would look cannot claim a hope that society recognizes as reasonable against something any member of the public could see or reach.³ The second prong carries most of the weight, because it is the prong that asks what the public is permitted to do. The facts of Katz show where the line falls. The government pointed out that the telephone booth was partly glass, so the petitioner was as visible inside it as he would have been outside. The Court answered that what he sought to keep out was the uninvited ear, and that being seen did not cost him protection against being overheard.⁴ Exposure therefore reaches only the information actually open to public perception: the petitioner's body was exposed through the glass, but his words were not.

The reason for the rule can be read off its structure. An officer who stands where any member of the public may lawfully stand and looks at what any member of the public could see takes nothing the person had kept back, so no private sphere has been entered. If the rule read otherwise, an officer walking down a public street would need a warrant before glancing at a front yard or an item on a porch table, and ordinary observation would become a constitutional event. A second reason concerns who can cheaply prevent the exposure. A person who wants something private can close the door or draw the blind, while an officer has no way of knowing in advance which exposed things an owner secretly meant to withhold. The same logic runs through the plain-view principle. In Horton v. California the Court explained that when an article is already in plain view, looking at it invades no privacy, although taking it is a separate question because a seizure intrudes on the owner's possessory interest.⁵

The rule has conditions that keep it from swallowing the privacy test. The officer must be lawfully in the place from which the observation is made, and the officer must rely on natural senses or a common aid. An officer lawfully present who detects something by sight, hearing, or smell conducts no search, but an officer who exceeds the permission under which they are present does conduct one. An officer who is allowed only to pick up and move a bag, but squeezes it to learn what is inside, has searched, as in Bond v. United States.⁶ A flashlight or binoculars changes nothing, because such aids only enhance what the public could see. A thermal imager aimed at a house is different. In Kyllo v. United States the Court held its use a search because the device is not in general public use and it obtains information about the home's interior that otherwise would require a physical intrusion.⁷ Observation also gives no right of entry: an officer on the public way who spots contraband through a window still needs a warrant or some other legal justification before going inside to take it.⁸

Those conditions matter most at the home. Viewing a residence from the public way, from a neighbor's property, or from the part of the curtilage that serves as the normal path to the door is generally no search, while straying from that path to peep through a window is a search, and so is any extraordinary effort to overcome the resident's reasonable attempts to keep the curtilage private.⁹ The exposure rule also leaves the property route untouched. A resident whose yard can be seen from the street has exposed what the eye can reach but has invited no one onto the lawn, so an officer who physically enters the curtilage to gather information still searches under the property route, and either route is enough to establish a search.¹⁰

A rule about looking cannot be stretched into a rule about entering. The exam trap is to see a window, a yard, or a visible object in the facts, conclude that plain view ends the analysis, and overlook that observation from a lawful vantage point is all the exposure rule excuses. In the first version above, the glance was free, but walking through the door to take the pistol would have required a warrant or another justification.

Nothing in the rule confines it to residences. In Marshall v. Western Waterproofing Co. the Eighth Circuit rejected an employer's claim that inspectors had searched illegally when they examined scaffolding hanging on the outside of a building, reasoning that the scaffolding was exposed to public view and readily observable by the building's tenants, so the employer could have no reasonable expectation of privacy in the viewing.¹¹ The inspectors also viewed it from an office whose occupant had consented to their presence, so their vantage point was lawful. Courts applying the same logic online treat information shared with an audience as exposed to that audience. In United States v. Meregildo the defendant's Facebook posts were visible to his friends, and the government saw them through a cooperating witness who was one of those friends. The court held that his expectation of privacy ended when he disseminated the posts to friends who were free to share them with the government.¹² A federal district court reached the same result in United States v. Gatson, where police created a fake Instagram account and the defendant accepted its follow request, and it held that no warrant is required for the consensual sharing of that kind of information, even when the accepted friend is the police.¹³ The court in Harris went further and compared a broadcast tweet to a person who opens a window and screams, with the platform in the position of the witness who heard.¹⁴

The audience is what decides these cases. A court confronting a student's online accounts separated wall posts that her friends could see from private messages that worked like email between two people, compared the messages to a private letter, and found a reasonable expectation of privacy in them.¹⁵ These are lower-court applications rather than Supreme Court holdings, but they track the distinction drawn in Katz between what a person shares with an audience and what a person confines to a chosen recipient behind a closed door.

The two applications that follow, aerial observation of a fenced yard and the search of garbage left at the curb, each present an officer who learned something from a place the public could reach. Each is resolved by the second step of this sequence, which asks whether society recognizes an expectation of privacy against what any member of the public could see or collect from that spot.

Aerial Observation

The first of the two applications puts the exposure rule to work where privacy expectations run highest, in the fenced yard beside a house. In California v. Ciraolo the Santa Clara police received an anonymous tip that marijuana was growing in the respondent's backyard, but a 6-foot outer fence and a 10-foot inner fence enclosed the yard and blocked any view from the ground.¹⁷ The officers, both trained in marijuana identification, secured a private plane and flew over the house at 1,000 feet, within navigable airspace. From that height they readily identified plants eight to ten feet tall growing in a plot roughly 15 by 25 feet, photographed the plot with a standard 35mm camera, and used what they saw to obtain a search warrant.¹⁸ The Court held that the aerial observation was not a search, because any member of the public flying in that lawful airspace could have seen the same things with the naked eye.¹⁹

The Court reached that result by running the two-part privacy test. Ciraolo's fence was evidence that he wanted the crop hidden from street-level views, and because the State had not challenged the finding that he held an actual expectation of privacy, the Court did not need to resolve the first prong.²⁰ It did note that a 10-foot fence would not shield the plants from a person perched on a truck or a two-level bus, which left unclear whether he expected privacy from all observation or merely hoped that no one would notice his gardening.²¹ The decision therefore turns on the second prong, which asks whether society is prepared to treat the expectation as reasonable.

The Court accepted that the yard lay within the curtilage, the area immediately adjacent to a home to which the intimate activity of domestic life extends, and it acknowledged that curtilage protection exists for families and personal privacy in a space where expectations are most heightened.²² Curtilage status nonetheless does not bar all police observation. The Fourth Amendment has never required officers to shield their eyes while passing a home on a public thoroughfare, and an owner's steps to block some views do not prevent an officer from looking from a public vantage point where the officer has a right to be and from which the activity is clearly visible.²³ The reason follows from what a fence does. A fence defeats only the views it blocks, so above its top line the yard stays as open to a passing aircraft as it is to anyone on a neighboring roof, and an owner who cannot screen the sky has no basis to expect that no one lawfully overhead will look down. Curtilage status answers how strongly the surroundings of a home are shielded against intrusion; it leaves open what a lawfully positioned observer may see.

Ciraolo also argued that a viewing motivated by a law-enforcement purpose, rather than a casual or accidental glance, should require a warrant.²⁴ The holding rejects any such distinction, since the officers flew over only because of a tip and the observation was still no search.²⁵ What matters is what the public vantage point can reveal, and the observer's reason for looking does not change that. This is consistent with the rule from the preceding section, under which an officer's suspicion neither enlarges nor shrinks what a lawful visitor may do.

The second qualifier explains the care the Court has taken in other aerial cases. In the companion case, Dow Chemical Co. v. United States, aerial photography of an industrial complex was held to be no search, but the Court indicated that the answer might differ if the surveillance reached an area immediately adjacent to a private home, captured identifiable faces or secret documents, or used highly sophisticated equipment not generally available to the public.²⁹ The home-adjacent caveat does not displace Ciraolo, where the observed area was curtilage and the observation was still no search. The place observed therefore does not decide the case alone; the vantage point and the means of observation do.

The third qualifier keeps the aerial rule from spreading to ground entries. In Florida v. Jardines police brought a drug-detection dog onto private property without permission, and that trespass on a protected area was a search under the property route even though the conduct was not a search under the privacy test.³⁰ The same yard that officers may view from the air is thus one they may not walk into to gather information, absent permission or another legal justification.

The dissent in Ciraolo would have decided the case the other way, and its objections frame the technology theme that develops in later cases. It reasoned that the privacy test replaced a standard keyed to physical invasion of a protected area because that older standard gives no real protection against surveillance techniques that technology makes possible, since police can now see and hear people's activities without being physically nearby.³¹ It also called the majority's rejection of Ciraolo's expectation of privacy in his yard conclusory, and it found that rejection at odds with the Court's own reaffirmation of the curtilage doctrine, including the companion case's recognition that society accepts as reasonable expectations of privacy in the area immediately surrounding a home.³² The majority's answer lies in its holding: curtilage protects against intrusion, and naked-eye viewing from public airspace is not an intrusion. The dissent states the other side of that choice, which matters because a rule built on what ordinary senses can see from a public place grows less certain as surveillance tools improve.

That uncertainty is why the technology limit sits at the edge of the rule. Common aids such as flashlights and binoculars leave the answer unchanged, but sense-enhancing technology that reveals the interior of a home and is not in general public use does not, and in Kyllo v. United States the use of a thermal imager was held to be a search.³³ How the same concern operates when the information is digital rather than visual is taken up in the later section on location data and third parties.

On an exam, the usual error is to see a yard, a fence, and a plane in the facts and decide the issue by labeling the yard curtilage. Students lose this fact pattern by treating curtilage status as the end of the analysis, because the question is where the observers were and what they used to see, and a lawful vantage point with the naked eye answers it against the owner.³⁴

Curbside Garbage

The exposure rule reaches its most ordinary application in a bag of household trash. In California v. Greenwood a Laguna Beach investigator, Jenny Stracner, had information suggesting that Greenwood was trafficking in narcotics, and a neighbor had reported heavy late-night vehicle traffic at his house, with cars staying only a few minutes.³⁶ Stracner asked the regular trash collector to take the plastic bags Greenwood had left on the curb in front of his house and to hand them over without mixing in garbage from other homes. The collector complied, Stracner searched the bags and found items indicative of narcotics use, and she used what she found to support an affidavit for a warrant to search the home.³⁷ The Court held that there is no reasonable expectation of privacy in garbage left for collection outside the curtilage of a home, so police may search and seize it without a warrant or probable cause.³⁸ Because no search occurred, the strength of the tip never mattered, and the officers needed no justification at all to open the bags.

That result can sound odd to a layperson, since going through someone's trash looks like a search in the everyday sense. The word is a legal term of art, however, and many things the police do that an ordinary speaker would call searching, such as sifting through a suspect's garbage or watching a yard from an airplane, are not searches under the Fourth Amendment.³⁹ Whether conduct counts depends on the two-part privacy test, which asks whether the person showed an actual expectation of privacy and whether society is prepared to recognize that expectation as reasonable.⁴⁰ Greenwood's bags make the first prong easy to argue, because as the dissent describes the record they were sealed and opaque, which is about as much concealment as a person can supply.⁴¹ Whatever Greenwood hoped, the holding means that society does not accept as reasonable an expectation that no one will look inside a bag set out this way.⁴² A precaution that proves the first prong therefore does not settle the second.

The holding carries two limiting phrases, and each has its own logic. The phrase outside the curtilage fixes the location: the curtilage is the area immediately surrounding the home to which domestic life extends, and the curb lies beyond it, in a place open to passersby, scavengers, and the collector. The phrase left for collection fixes the purpose: a resident who sets out garbage means to hand it to a stranger whose job is to take it away, and that stranger may dump it, sort it, or pass it along as the work requires, with no control left to the resident. Both conditions are part of the rule as stated.⁴³ Together they explain why the rule rests on exposure. A bag at the curb is reachable by anyone and is delivered to a third party, so an expectation that the police alone will never look is one that society does not honor. The dissent's own account of the majority confirms the point, since it describes the majority as treating the access of snoops and other members of the public to curbside trash as what defeats the expectation of privacy.⁴⁴

The dissent supplies the argument a student should be able to state against the rule, although it does not state the law. Its first point is that a closed, opaque container keeps its protection wherever it is found, so a sealed trash bag is no different from a suitcase or a sealed package, and the police may not open it without a warrant.⁴⁵ Its second point is that trash is intimate, because a single bag reveals eating, reading, and recreational habits and can disclose health, finances, political leanings, and personal relationships.⁴⁶ Its third point is that society does recognize the expectation as reasonable, as shown by the public condemnation when a reporter went through a former Secretary of State's trash and published what he found.⁴⁷ The holding answers that the second prong asks who can reach the bag, and a detailed picture of private life inside it does not revive an expectation that exposure has already defeated.⁴⁸

Because the case addressed only curbside garbage, the rule does not follow the same bags into the curtilage.

That second analysis is the one applied in Florida v. Jardines, where police brought a drug-detection dog onto protected curtilage and conducted a search under the property route even though the conduct was not a search under the privacy test.⁴⁹ The curbside rule is a statement about exposure, and a porch inside the curtilage has not been exposed to the street in the way a bag at the curb has.

On an exam, the usual error is to treat every trash fact pattern as controlled by the curbside rule. Students lose points when they apply it to bags taken from inside the curtilage, because the rule depends on where the bag was and why it was there, and an entry onto the porch or into the yard is analyzed under the property route.⁵⁰