Justice Stewart
announced the judgment of the Court and delivered an opinion, in which Justice Brennan, Justice White, and Justice Marshall joined.
I
On the early morning of January 5, 1975, California Highway Patrol officers stopped the petitioner’s car — a 1966 Chevrolet station wagon — because he had been driving erratically. He got out of his vehicle and walked towards the patrol car. When one of the officers asked him for his driver’s license and the station wagon’s registration, he fumbled with his wallet. When the petitioner opened the car door to get out the registration, the officers smelled marihuana smoke. One of the officers patted down the petitioner, and discovered a vial of liquid. The officer then searched the passenger compartment of the car, and found marihuana as well as equipment for using it.
After putting the petitioner in the patrol car, the officers opened the tailgate of the station wagon, located a handle set flush in the deck, and lifted it up to uncover a recessed luggage compartment. In the compartment were a totebag and two packages wrapped in green opaque plastic. The police unwrapped the packages; each one contained 15 pounds of marihuana.
The petitioner was charged with various drug offenses, his pretrial motion to suppress the evidence found when the packages were unwrapped was denied, and a jury convicted him. In an unpublished opinion, the California Court of Appeal affirmed the judgment in all relevant respects. This Court granted a writ of certiorari, vacated the Court of Appeal’s judgment, and remanded the case for further consideration in light of Arkansas v. Sanders, 442 U. S. 753. 443 U. S. 903. On remand, the Court of Appeal again found the warrantless opening of the packages constitutionally permissible, since the trial court “could reasonably [have] conclude [d] that the contents of the packages could have been inferred from their outward appearance, so that appellant could not have held a reasonable expectation of privacy with respect to the contents.” 103 Cal. App. 3d 34, 40, 162 Cal. Rptr. 780, 783. Because of continuing uncertainty as to whether closed containers found during a lawful warrantless search of an automobile may themselves be searched without a warrant, this Court granted certiorari. 449 U. S. 1109.
II
The Fourth Amendment to the Constitution, which is made applicable to the States through the Fourteenth Amendment, establishes “[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures.” This Court has held that a search is per se unreasonable, and thus violates the Fourth Amendment, if the police making the search have not first secured from a neutral magistrate a warrant that satisfies the terms of the Warrant Clause of the Fourth Amendment. See, e. g., Katz v. United States, 389 U. S. 347, 357; Agnello v. United States, 269 U. S. 20, 33. Although the Court has identified some exceptions to this warrant requirement, the Court has emphasized that these exceptions are “few,” “specifically established,” and “well-delineated.” Katz v. United States, supra, at 357.
Among these exceptions is the so-called “automobile exception.” See Colorado v. Bannister, 449 U. S. 1. In Carroll v. United States, 267 U. S. 132, the Court held that a search warrant is unnecessary “where there is probable cause to search an automobile stopped on the highway; the car is movable, the occupants are alerted, and the car’s contents may never be found again if a warrant must be obtained.” Chambers v. Maroney, 399 U. S. 42, 51. In recent years, we have twice been confronted with the suggestion that this “automobile exception” somehow justifies the warrantless search of a closed container found inside an automobile. Each time, the Court has refused to accept the suggestion.
In United States v. Chadwick, 433 U. S. 1, the Government argued in part that luggage is analogous to motor vehicles for Fourth Amendment purposes, and that the “automobile exception” should thus be extended to encompass closed pieces of luggage. The Court rejected the analogy and insisted that the exception is confined to the special and possibly unique circumstances which were the occasion of its genesis. First, the Court said that “[o]ur treatment of automobiles has been based in part on their inherent mobility, which often makes obtaining a judicial warrant impracticable.” Id., at 12. While both cars and luggage may be “mobile,” luggage itself may be brought and kept under the control of the police.
Second, the Court acknowledged that “inherent mobility” cannot alone justify the automobile exception, since the Court has sometimes approved warrantless searches in which the automobile’s mobility was irrelevant. See Cady v. Dombrowski, 413 U. S. 433, 441-442; South Dakota v. Opperman, 428 U. S. 364, 367. The automobile exception, the Court said, is thus also supported by “the diminished expectation of privacy which surrounds the automobile” and which arises from the facts that a car is used for transportation and not as a residence or a repository of personal effects, that a car’s occupants and contents travel in plain view, and that automobiles are necessarily highly regulated by government. United States v. Chadwick, supra, at 12-13. No such diminished expectation of privacy characterizes luggage; on the contrary, luggage typically is a repository of personal effects, the contents of closed pieces of luggage are hidden from view, and luggage is not generally subject to state regulation.
In Arkansas v. Sanders, 442 U. S. 753, the State of Arkansas argued that the “automobile exception” should be extended to allow the warrantless search of everything found in an automobile during a lawful warrantless search of the vehicle itself. The Court rejected this argument for much the same reason it had rejected the Government’s argument in Chadwick. Pointing out, first, that “[o]nce police have seized a suitcase, as they did here, the extent of its mobility is in no way affected by the place from which it was taken,” the Court said that there generally “is no greater need for war-rantless searches of luggage taken from automobiles than of luggage taken from other places.” 442 U. S., at 763-764. Second, the Court saw no reason to believe that the privacy expectation in a closed piece of luggage taken from a car is necessarily less than the privacy expectation in closed pieces of luggage found elsewhere.
In the present case, the Court once again encounters the argument — made in the Government’s brief as amicus curiae— that the contents of a closed container carried in a vehicle are somehow not fully protected by the Fourth Amendment. But this argument is inconsistent with the Court’s decisions in Chadwick and Sanders. Those cases made clear, if it was not clear before, that a closed piece of luggage found in a lawfully searched car is constitutionally protected to the same extent as are closed pieces of luggage found anywhere else.
The .respondent, however, proposes that the nature of a container may diminish the constitutional protection to which it otherwise would be entitled — that the Fourth Amendment protects only containers commonly used to transport “personal effects.” By personal effects the respondent means property worn on or carried about the person or having some intimate relation to the person. In taking this position, the respondent relies on numerous opinions that have drawn a distinction between pieces of sturdy luggage, like suitcases, and flimsier containers, like cardboard boxes. Compare, e. g., United States v. Benson, 631 F. 2d 1336 (CA8 1980) (leather totebag); United States v. Miller, 608 F. 2d 1089 (CA5 1979) (plastic portfolio); United States v. Presler, 610 F. 2d 1206 (CA4 1979) (briefcase); United States v. Meier, 602 F. 2d 253 (CA10 1979) (backpack); United States v. Johnson, 588 F. 2d 147 (CA5 1979) (duffelbag); United States v. Stevie, 582 F. 2d 1175 (CA8 1978), with United States v. Mannino, 635 F. 2d 110 (CA2 1980) (plastic bag inside paper bag); United States v. Goshorn, 628 F. 2d 697, 699 (CA1 1980) (“([t]wo plastic bags, further in three brown paper bags, further in two clear plastic bags’ ”); United States v. Gooch, 603 F. 2d 122 (CA10 1979) (plastic bag); United States v. Mackey, 626 F. 2d 684 (CA9 1980) (paper bag); United States v. Neumann, 585 F. 2d 355 (CA8 1978) (cardboard box).
The respondent’s argument cannot prevail for at least two reasons. First, it has no basis in the language or meaning of the Fourth Amendment. That Amendment protects people and their effects, and it protects those effects whether they are “personal” or “impersonal.” The contents of Chadwick’s footlocker and Sanders’ suitcase were immune from a warrantless search because they had been placed within a closed, opaque container and because Chadwick and Sanders had thereby reasonably “manifested an expectation that the contents would remain free from public examination.” United States v. Chadwick, supra, at 11. Once placed within such a container, a diary and a dishpan are equally protected by the Fourth Amendment.
Second, even if one wished to import such a distinction into the Fourth Amendment, it is difficult if not impossible to perceive any objective criteria by which that task might be accomplished. What one person may put into a suitcase, another may put into a paper bag. United States v. Ross, 210 U. S. App. D. C. 342, 655 F. 2d 1159 (1981) (en banc). And as the disparate results in the decided cases indicate, no court, no constable, no citizen, can sensibly be asked to distinguish the relative “privacy interests” in a closed suitcase, briefcase, portfolio, duffelbag, or box.
The respondent protests that footnote 13 of the Sanders opinion says that “[n]ot all containers and packages found by police during the course of a search will deserve the full protection of the Fourth Amendment.” 442 U. S., at 764, n. 13. But the exceptions listed in the succeeding sentences of the footnote are the very model of exceptions which prove the rule: “Thus, some containers (for example a kit of burglar tools or a gun case) by their very nature cannot support any reasonable expectation of privacy because their contents can be inferred from their outward appearance. Similarly, in some cases the contents of a package will be open to ‘plain view/ thereby obviating the need for a warrant.” Id., at 764-765, n. 13. The second of these exceptions obviously refers to items in a container that is not closed. The first exception is likewise little more than another variation of the “plain view” exception, since, if the distinctive configuration of a container proclaims its contents, the contents cannot fairly be said to have been removed from a searching officer’s view. The same would be true, of course, if the container were transparent, or otherwise clearly revealed its contents. In short, the negative implication of footnote 13 of the Sanders opinion is that, unless the container is such that its contents may be said to be in plain view, those contents are fully protected by the Fourth Amendment.
The California Court of Appeal believed that the packages in the present case fell directly within the second exception described in this footnote, since “[a]ny experienced observer could have inferred from the appearance of the packages that they contained bricks of marijuana.” 103 Cal. App. 3d, at 40, 162 Cal. Rptr., at 783. The only evidence the court cited to support this proposition was the testimony of one of the officers who arrested the petitioner. When asked whether there was anything about “these two plastic wrapped green blocks which attracted your attention,” the officer replied, somewhat obscurely:
“A. I had previous knowledge of transportation of such blocks. Normally contraband is wrapped this way, merely hearsay. I had never seen them before.
“Q. You had heard contraband was packaged this way?
“A. Yes.” Id., at 40, n. 2, 162 Cal. Rptr., at 783, n. 4.
This vague testimony certainly did not establish that marihuana is ordinarily “packaged this way.” Expectations of privacy are established by general social norms, and to fall within the second exception of the footnote in question a container must so clearly announce its contents, whether by its distinctive configuration, its transparency, or otherwise, that its contents are obvious to an observer. If indeed a green plastic wrapping reliably indicates that a package could only contain marihuana, that fact was not shown by the evidence of record in this case.
Although the two bricks of marihuana were discovered during a lawful search of the petitioner’s car, they were inside a closed, opaque container. We reaffirm today that such a container may not be opened without a warrant, even if it is found during the course of the lawful search of an automobile. Since the respondent does not allege the presence of any circumstances that would constitute a valid exception to this general rule, it is clear that the opening of the closed containers without a search warrant violated the Fourth and Fourteenth Amendments. Accordingly, the judgment of the California Court of Appeal is reversed.
It is so ordered.
The Chief Justice concurs in the judgment.
‘■A photograph was made of one of the packages, and it was later described as follows:
“The package visible in the photograph is apparently wrapped or boxed in an opaque material covered by an outer wrapping of transparent, cellophane-type plastic. (The photograph is not in color, and the ‘green’ plastic cannot be seen at all.) Both wrappings are sealed on the outside with at least one strip of opaque tape. As thus wrapped and sealed, the package roughly resembles an oversized, extra-long cigar box with slightly rounded corners and edges. It bears no legend or other written indicia supporting any inference concerning its contents.” 103 Cal. App. 3d 34, 44, 162 Cal. Rptr. 780, 785 (Rattigan, J., dissenting).
As Judge Rattigan wrote in his dissenting opinion in the California Court of Appeal: “For all that I see, it could contain books, stationery, canned goods, or any number of other wholly innocuous items which might be heavy in weight. In fact, it bears a remarkable resemblance to an unlabelled carton of emergency highway flares that I bought from a store shelf and have carried in the trunk of my own automobile.” 103 Cal. App. 3d, at 44, 162 Cal. Rptr., at 785.
In particular, it is not argued that the opening of the packages was incident to a lawful custodial arrest. Cf. Chimel v. California, 395 U. S. 752. See Arkansas v. Sanders, 442 U. S. 753, 764, n. 11. Further, the respondent does not argue that the petitioner consented to the opening of the packages.