Task: sc_issuearea

What follows is an opinion from the Supreme Court of the United States. Your task is to determine the issue area of the Court's decision. Determine the issue area on the basis of the Court's own statements as to what the case is about. Focus on the subject matter of the controversy rather than its legal basis. In specifying the issue in a legacy case, choose the one that best accords with what today's Court would consider it to be. Choose among the following issue areas: "Criminal Procedure" encompasses the rights of persons accused of crime, except for the due process rights of prisoners. "Civil rights" includes non-First Amendment freedom cases which pertain to classifications based on race (including American Indians), age, indigency, voting, residency, military or handicapped status, gender, and alienage. "First Amendment encompasses the scope of this constitutional provision, but do note that it need not involve the interpretation and application of a provision of the First Amendment. For example, if the case only construe a precedent, or the reviewability of a claim based on the First Amendment, or the scope of an administrative rule or regulation that impacts the exercise of First Amendment freedoms. "Due process" is limited to non-criminal guarantees. "Privacy" concerns libel, comity, abortion, contraceptives, right to die, and Freedom of Information Act and related federal or state statutes or regulations. "Attorneys" includes attorneys' compensation and licenses, along with trhose of governmental officials and employees. "Unions" encompass those issues involving labor union activity. "Economic activity" is largely commercial and business related; it includes tort actions and employee actions vis-a-vis employers. "Judicial power" concerns the exercise of the judiciary's own power. "Federalism" pertains to conflicts and other relationships between the federal government and the states, except for those between the federal and state courts. "Federal taxation" concerns the Internal Revenue Code and related statutes. "Private law" relates to disputes between private persons involving real and personal property, contracts, evidence, civil procedure, torts, wills and trusts, and commercial transactions. Prior to the passage of the Judges' Bill of 1925 much of the Court's cases concerned such issues. Use "Miscellaneous" for legislative veto and executive authority vis-a-vis congress or the states.

Chief Justice ROBERTS delivered the opinion of the Court.
These two cases raise a common question: whether the police may, without a warrant, search digital information on a cell phone seized from an individual who has been arrested.
I
A
In the first case, petitioner David Riley was stopped by a police officer for driving with expired registration tags. In the course of the stop, the officer also learned that Riley's license had been suspended. The officer impounded Riley's car, pursuant to department policy, and another officer conducted an inventory search of the car. Riley was arrested for possession of concealed and loaded firearms when that search turned up two handguns under the car's hood. See Cal.Penal Code Ann. §§ 12025(a)(1), 12031(a)(1) (West 2009).
An officer searched Riley incident to the arrest and found items associated with the "Bloods" street gang. He also seized a cell phone from Riley's pants pocket. According to Riley's uncontradicted assertion, the phone was a "smart phone," a cell phone with a broad range of other functions based on advanced computing capability, large storage capacity, and Internet connectivity. The officer accessed information on the phone and noticed that some words (presumably in text messages or a contacts list) were preceded by the letters "CK"-a label that, he believed, stood for "Crip Killers," a slang term for members of the Bloods gang.
At the police station about two hours after the arrest, a detective specializing in gangs further examined the contents of the phone. The detective testified that he "went through" Riley's phone "looking for evidence, because... gang members will often video themselves with guns or take pictures of themselves with the guns." App. in No. 13-132, p. 20. Although there was "a lot of stuff" on the phone, particular files that "caught [the detective's] eye" included videos of young men sparring while someone yelled encouragement using the moniker "Blood." Id., at 11-13. The police also found photographs of Riley standing in front of a car they suspected had been involved in a shooting a few weeks earlier.
Riley was ultimately charged, in connection with that earlier shooting, with firing at an occupied vehicle, assault with a semiautomatic firearm, and attempted murder. The State alleged that Riley had committed those crimes for the benefit of a criminal street gang, an aggravating factor that carries an enhanced sentence. Compare Cal.Penal Code Ann. § 246 (2008) with § 186.22(b)(4)(B) (2014). Prior to trial, Riley moved to suppress all evidence that the police had obtained from his cell phone. He contended that the searches of his phone violated the Fourth Amendment, because they had been performed without a warrant and were not otherwise justified by exigent circumstances. The trial court rejected that argument. App. in No. 13-132, at 24, 26. At Riley's trial, police officers testified about the photographs and videos found on the phone, and some of the photographs were admitted into evidence. Riley was convicted on all three counts and received an enhanced sentence of 15 years to life in prison.
The California Court of Appeal affirmed. No. D059840 (Cal. App., Feb. 8, 2013), App. to Pet. for Cert. in No. 13-132, pp. 1a-23a. The court relied on the California Supreme Court's decision in People v. Diaz, 51 Cal.4th 84, 119 Cal.Rptr.3d 105, 244 P.3d 501 (2011), which held that the Fourth Amendment permits a warrantless search of cell phone data incident to an arrest, so long as the cell phone was immediately associated with the arrestee's person. See id., at 93, 119 Cal.Rptr.3d 105, 244 P.3d, at 505-506.
The California Supreme Court denied Riley's petition for review, App. to Pet. for Cert. in No. 13-132, at 24a, and we granted certiorari, 571 U.S. ----, 132 S.Ct. 94, 181 L.Ed.2d 23 (2014).
B
In the second case, a police officer performing routine surveillance observed respondent Brima Wurie make an apparent drug sale from a car. Officers subsequently arrested Wurie and took him to the police station. At the station, the officers seized two cell phones from Wurie's person. The one at issue here was a "flip phone," a kind of phone that is flipped open for use and that generally has a smaller range of features than a smart phone. Five to ten minutes after arriving at the station, the officers noticed that the phone was repeatedly receiving calls from a source identified as "my house" on the phone's external screen. A few minutes later, they opened the phone and saw a photograph of a woman and a baby set as the phone's wallpaper. They pressed one button on the phone to access its call log, then another button to determine the phone number associated with the "my house" label. They next used an online phone directory to trace that phone number to an apartment building.
When the officers went to the building, they saw Wurie's name on a mailbox and observed through a window a woman who resembled the woman in the photograph on Wurie's phone. They secured the apartment while obtaining a search warrant and, upon later executing the warrant, found and seized 215 grams of crack cocaine, marijuana, drug paraphernalia, a firearm and ammunition, and cash.
Wurie was charged with distributing crack cocaine, possessing crack cocaine with intent to distribute, and being a felon in possession of a firearm and ammunition. See 18 U.S.C. § 922(g); 21 U.S.C. § 841(a). He moved to suppress the evidence obtained from the search of the apartment, arguing that it was the fruit of an unconstitutional search of his cell phone. The District Court denied the motion. 612 F.Supp.2d 104 (Mass.2009). Wurie was convicted on all three counts and sentenced to 262 months in prison.
A divided panel of the First Circuit reversed the denial of Wurie's motion to suppress and vacated Wurie's convictions for possession with intent to distribute and possession of a firearm as a felon. 728 F.3d 1 (2013). The court held that cell phones are distinct from other physical possessions that may be searched incident to arrest without a warrant, because of the amount of personal data cell phones contain and the negligible threat they pose to law enforcement interests. See id., at 8-11.
We granted certiorari. 571 U.S. ----, 134 S.Ct. 999, 187 L.Ed.2d 848 (2014).
II
The Fourth Amendment provides:
"The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized."
As the text makes clear, "the ultimate touchstone of the Fourth Amendment is'reasonableness.' " Brigham City v. Stuart, 547 U.S. 398, 403, 126 S.Ct. 1943, 164 L.Ed.2d 650 (2006). Our cases have determined that "[w]here a search is undertaken by law enforcement officials to discover evidence of criminal wrongdoing,... reasonableness generally requires the obtaining of a judicial warrant." Vernonia School Dist. 47J v. Acton, 515 U.S. 646, 653, 115 S.Ct. 2386, 132 L.Ed.2d 564 (1995). Such a warrant ensures that the inferences to support a search are "drawn by a neutral and detached magistrate instead of being judged by the officer engaged in the often competitive enterprise of ferreting out crime." Johnson v. United States, 333 U.S. 10, 14, 68 S.Ct. 367, 92 L.Ed. 436 (1948). In the absence of a warrant, a search is reasonable only if it falls within a specific exception to the warrant requirement. See Kentucky v. King, 563 U.S. ----, ----, 131 S.Ct. 1849, 1856-1857, 179 L.Ed.2d 865 (2011).
The two cases before us concern the reasonableness of a warrantless search incident to a lawful arrest. In 1914, this Court first acknowledged in dictum "the right on the part of the Government, always recognized under English and American law, to search the person of the accused when legally arrested to discover and seize the fruits or evidences of crime." Weeks v. United States, 232 U.S. 383, 392, 34 S.Ct. 341, 58 L.Ed. 652. Since that time, it has been well accepted that such a search constitutes an exception to the warrant requirement. Indeed, the label "exception" is something of a misnomer in this context, as warrantless searches incident to arrest occur with far greater frequency than searches conducted pursuant to a warrant. See 3 W. LaFave, Search and Seizure § 5.2(b), p. 132, and n. 15 (5th ed. 2012).
Although the existence of the exception for such searches has been recognized for a century, its scope has been debated for nearly as long. See Arizona v. Gant, 556 U.S. 332, 350, 129 S.Ct. 1710, 173 L.Ed.2d 485 (2009) (noting the exception's "checkered history"). That debate has focused on the extent to which officers may search property found on or near the arrestee. Three related precedents set forth the rules governing such searches:
The first, Chimel v. California, 395 U.S. 752, 89 S.Ct. 2034, 23 L.Ed.2d 685 (1969), laid the groundwork for most of the existing search incident to arrest doctrine. Police officers in that case arrested Chimel inside his home and proceeded to search his entire three-bedroom house, including the attic and garage. In particular rooms, they also looked through the contents of drawers. Id., at 753-754, 89 S.Ct. 2034.
The Court crafted the following rule for assessing the reasonableness of a search incident to arrest:
"When an arrest is made, it is reasonable for the arresting officer to search the person arrested in order to remove any weapons that the latter might seek to use in order to resist arrest or effect his escape. Otherwise, the officer's safety might well be endangered, and the arrest itself frustrated. In addition, it is entirely reasonable for the arresting officer to search for and seize any evidence on the arrestee's person in order to prevent its concealment or destruction.... There is ample justification, therefore, for a search of the arrestee's person and the area 'within his immediate control'-construing that phrase to mean the area from within which he might gain possession of a weapon or destructible evidence." Id., at 762-763, 89 S.Ct. 2034.
The extensive warrantless search of Chimel's home did not fit within this exception, because it was not needed to protect officer safety or to preserve evidence. Id., at 763, 768, 89 S.Ct. 2034.
Four years later, in United States v. Robinson, 414 U.S. 218, 94 S.Ct. 467, 38 L.Ed.2d 427 (1973), the Court applied the Chimel analysis in the context of a search of the arrestee's person. A police officer had arrested Robinson for driving with a revoked license. The officer conducted a patdown search and felt an object that he could not identify in Robinson's coat pocket. He removed the object, which turned out to be a crumpled cigarette package, and opened it. Inside were 14 capsules of heroin. Id., at 220, 223, 89 S.Ct. 2034.
The Court of Appeals concluded that the search was unreasonable because Robinson was unlikely to have evidence of the crime of arrest on his person, and because it believed that extracting the cigarette package and opening it could not be justified as part of a protective search for weapons. This Court reversed, rejecting the notion that "case-by-case adjudication" was required to determine "whether or not there was present one of the reasons supporting the authority for a search of the person incident to a lawful arrest." Id., at 235, 89 S.Ct. 2034. As the Court explained, "[t]he authority to search the person incident to a lawful custodial arrest, while based upon the need to disarm and to discover evidence, does not depend on what a court may later decide was the probability in a particular arrest situation that weapons or evidence would in fact be found upon the person of the suspect." Ibid. Instead, a "custodial arrest of a suspect based on probable cause is a reasonable intrusion under the Fourth Amendment; that intrusion being lawful, a search incident to the arrest requires no additional justification." Ibid.
The Court thus concluded that the search of Robinson was reasonable even though there was no concern about the loss of evidence, and the arresting officer had no specific concern that Robinson might be armed. Id., at 236, 89 S.Ct. 2034.
In doing so, the Court did not draw a line between a search of Robinson's person and a further examination of the cigarette pack found during that search. It merely noted that, "[h]aving in the course of a lawful search come upon the crumpled package of cigarettes, [the officer] was entitled to inspect it." Ibid. A few years later, the Court clarified that this exception was limited to "personal property... immediately associated with the person of the arrestee." United States v. Chadwick, 433 U.S. 1, 15, 97 S.Ct. 2476, 53 L.Ed.2d 538 (1977) (200-pound, locked footlocker could not be searched incident to arrest), abrogated on other grounds by California v. Acevedo, 500 U.S. 565, 111 S.Ct. 1982, 114 L.Ed.2d 619 (1991).
The search incident to arrest trilogy concludes with Gant, which analyzed searches of an arrestee's vehicle. Gant, like Robinson, recognized that the Chimel concerns for officer safety and evidence preservation underlie the search incident to arrest exception. See 556 U.S., at 338, 129 S.Ct. 1710. As a result, the Court concluded that Chimel could authorize police to search a vehicle "only when the arrestee is unsecured and within reaching distance of the passenger compartment at the time of the search." 556 U.S., at 343, 129 S.Ct. 1710.Gant added, however, an independent exception for a warrantless search of a vehicle's passenger compartment "when it is'reasonable to believe evidence relevant to the crime of arrest might be found in the vehicle.' " Ibid. (quoting Thornton v. United States, 541 U.S. 615, 632, 124 S.Ct. 2127, 158 L.Ed.2d 905 (2004) (SCALIA, J., concurring in judgment)). That exception stems not from Chimel, the Court explained, but from "circumstances unique to the vehicle context." 556 U.S., at 343, 129 S.Ct. 1710.
III
These cases require us to decide how the search incident to arrest doctrine applies to modern cell phones, which are now such a pervasive and insistent part of daily life that the proverbial visitor from Mars might conclude they were an important feature of human anatomy. A smart phone of the sort taken from Riley was unheard of ten years ago; a significant majority of American adults now own such phones. See A. Smith, Pew Research Center, Smartphone Ownership-2013 Update (June 5, 2013). Even less sophisticated phones like Wurie's, which have already faded in popularity since Wurie was arrested in 2007, have been around for less than 15 years. Both phones are based on technology nearly inconceivable just a few decades ago, when Chimel and Robinson were decided.
Absent more precise guidance from the founding era, we generally determine whether to exempt a given type of search from the warrant requirement "by assessing, on the one hand, the degree to which it intrudes upon an individual's privacy and, on the other, the degree to which it is needed for the promotion of legitimate governmental interests." Wyoming v. Houghton, 526 U.S. 295, 300, 119 S.Ct. 1297, 143 L.Ed.2d 408 (1999). Such a balancing of interests supported the search incident to arrest exception in Robinson, and a mechanical application of Robinson might well support the warrantless searches at issue here.
But while Robinson's categorical rule strikes the appropriate balance in the context of physical objects, neither of its rationales has much force with respect to digital content on cell phones. On the government interest side, Robinson concluded that the two risks identified in Chimel-harm to officers and destruction of evidence-are present in all custodial arrests. There are no comparable risks when the search is of digital data. In addition, Robinson regarded any privacy interests retained by an individual after arrest as significantly diminished by the fact of the arrest itself. Cell phones, however, place vast quantities of personal information literally in the hands of individuals. A search of the information on a cell phone bears little resemblance to the type of brief physical search considered in Robinson.
We therefore decline to extend Robinson to searches of data on cell phones, and hold instead that officers must generally secure a warrant before conducting such a search.
A
We first consider each Chimel concern in turn. In doing so, we do not overlook Robinson's admonition that searches of a person incident to arrest, "while based upon the need to disarm and to discover evidence," are reasonable regardless of "the probability in a particular arrest situation that weapons or evidence would in fact be found." 414 U.S., at 235, 94 S.Ct. 467. Rather than requiring the "case-by-case adjudication" that Robinson rejected, ibid., we ask instead whether application of the search incident to arrest doctrine to this particular category of effects would "untether the rule from the justifications underlying the Chimel exception," Gant,supra, at 343, 129 S.Ct. 1710. See also Knowles v. Iowa, 525 U.S. 113, 119, 119 S.Ct. 484, 142 L.Ed.2d 492 (1998) (declining to extend Robinson to the issuance of citations, "a situation where the concern for officer safety is not present to the same extent and the concern for destruction or loss of evidence is not present at all").
1
Digital data stored on a cell phone cannot itself be used as a weapon to harm an arresting officer or to effectuate the arrestee's escape. Law enforcement officers remain free to examine the physical aspects of a phone to ensure that it will not be used as a weapon-say, to determine whether there is a razor blade hidden between the phone and its case. Once an officer has secured a phone and eliminated any potential physical threats, however, data on the phone can endanger no one.
Perhaps the same might have been said of the cigarette pack seized from Robinson's pocket. Once an officer gained control of the pack, it was unlikely that Robinson could have accessed the pack's contents. But unknown physical objects may always pose risks, no matter how slight, during the tense atmosphere of a custodial arrest. The officer in Robinson testified that he could not identify the objects in the cigarette pack but knew they were not cigarettes. See 414 U.S., at 223, 236, n. 7, 94 S.Ct. 467. Given that, a further search was a reasonable protective measure. No such unknowns exist with respect to digital data. As the First Circuit explained, the officers who searched Wurie's cell phone "knew exactly what they would find therein: data. They also knew that the data could not harm them." 728 F.3d, at 10.
The United States and California both suggest that a search of cell phone data might help ensure officer safety in more indirect ways, for example by alerting officers that confederates of the arrestee are headed to the scene. There is undoubtedly a strong government interest in warning officers about such possibilities, but neither the United States nor California offers evidence to suggest that their concerns are based on actual experience. The proposed consideration would also represent a broadening of Chimel's concern that an arrestee himself might grab a weapon and use it against an officer "to resist arrest or effect his escape." 395 U.S., at 763, 89 S.Ct. 2034. And any such threats from outside the arrest scene do not "lurk[ ] in all custodial arrests." Chadwick, 433 U.S., at 14-15, 97 S.Ct. 2476. Accordingly, the interest in protecting officer safety does not justify dispensing with the warrant requirement across the board. To the extent dangers to arresting officers may be implicated in a particular way in a particular case, they are better addressed through consideration of case-specific exceptions to the warrant requirement, such as the one for exigent circumstances. See, e.g., Warden, Md. Penitentiary v. Hayden, 387 U.S. 294, 298-299, 87 S.Ct. 1642, 18 L.Ed.2d 782 (1967) ("The Fourth Amendment does not require police officers to delay in the course of an investigation if to do so would gravely endanger their lives or the lives of others.").
2
The United States and California focus primarily on the second Chimel rationale: preventing the destruction of evidence.
Both Riley and Wurie concede that officers could have seized and secured their cell phones to prevent destruction of evidence while seeking a warrant. See Brief for Petitioner in No. 13-132, p. 20; Brief for Respondent in No. 13-212, p. 41. That is a sensible concession. See Illinois v. McArthur, 531 U.S. 326, 331-333, 121 S.Ct. 946, 148 L.Ed.2d 838 (2001); Chadwick, supra, at 13, and n. 8, 97 S.Ct. 2476. And once law enforcement officers have secured a cell phone, there is no longer any risk that the arrestee himself will be able to delete incriminating data from the phone.
The United States and California argue that information on a cell phone may nevertheless be vulnerable to two types of evidence destruction unique to digital data-remote wiping and data encryption. Remote wiping occurs when a phone, connected to a wireless network, receives a signal that erases stored data. This can happen when a third party sends a remote signal or when a phone is preprogrammed to delete data upon entering or leaving certain geographic areas (so-called "geofencing"). See Dept. of Commerce, National Institute of Standards and Technology, R. Ayers, S. Brothers, & W. Jansen, Guidelines on Mobile Device Forensics (Draft) 29, 31 (SP 800-101 Rev. 1, Sept. 2013) (hereinafter Ayers). Encryption is a security feature that some modern cell phones use in addition to password protection. When such phones lock, data becomes protected by sophisticated encryption that renders a phone all but "unbreakable" unless police know the password. Brief for United States as Amicus Curiae in No. 13-132, p. 11.
As an initial matter, these broader concerns about the loss of evidence are distinct from Chimel's focus on a defendant who responds to arrest by trying to conceal or destroy evidence within his reach. See 395 U.S., at 763-764, 89 S.Ct. 2034. With respect to remote wiping, the Government's primary concern turns on the actions of third parties who are not present at the scene of arrest. And data encryption is even further afield. There, the Government focuses on the ordinary operation of a phone's security features, apart from any active attempt by a defendant or his associates to conceal or destroy evidence upon arrest.
We have also been given little reason to believe that either problem is prevalent. The briefing reveals only a couple of anecdotal examples of remote wiping triggered by an arrest. See Brief for Association of State Criminal Investigative Agencies et al. as Amici Curiae in No. 13-132, pp. 9-10; see also Tr. of Oral Arg. in No. 13-132, p. 48. Similarly, the opportunities for officers to search a password-protected phone before data becomes encrypted are quite limited. Law enforcement officers are very unlikely to come upon such a phone in an unlocked state because most phones lock at the touch of a button or, as a default, after some very short period of inactivity. See, e.g., iPhone User Guide for iOS 7.1 Software 10 (2014) (default lock after about one minute). This may explain why the encryption argument was not made until the merits stage in this Court, and has never been considered by the Courts of Appeals.
Moreover, in situations in which an arrest might trigger a remote-wipe attempt or an officer discovers an unlocked phone, it is not clear that the ability to conduct a warrantless search would make much of a difference. The need to effect the arrest, secure the scene, and tend to other pressing matters means that law enforcement officers may well not be able to turn their attention to a cell phone right away. See Tr. of Oral Arg. in No. 13-132, at 50; see also Brief for United States as Amicus Curiae in No. 13-132, at 19. Cell phone data would be vulnerable to remote wiping from the time an individual anticipates arrest to the time any eventual search of the phone is completed, which might be at the station house hours later. Likewise, an officer who seizes a phone in an unlocked state might not be able to begin his search in the short time remaining before the phone locks and data becomes encrypted.
In any event, as to remote wiping, law enforcement is not without specific means to address the threat. Remote wiping can be fully prevented by disconnecting a phone from the network. There are at least two simple ways to do this: First, law enforcement officers can turn the phone off or remove its battery. Second, if they are concerned about encryption or other potential problems, they can leave a phone powered on and place it in an enclosure that isolates the phone from radio waves. See Ayers 30-31. Such devices are commonly called "Faraday bags," after the English scientist Michael Faraday. They are essentially sandwich bags made of aluminum foil: cheap, lightweight, and easy to use. See Brief for Criminal Law Professors as Amici Curiae 9. They may not be a complete answer to the problem, see Ayers 32, but at least for now they provide a reasonable response. In fact, a number of law enforcement agencies around the country already encourage the use of Faraday bags. See, e.g., Dept. of Justice, National Institute of Justice, Electronic Crime Scene Investigation: A Guide for First Responders 14, 32 (2d ed. Apr. 2008); Brief for Criminal Law Professors as Amici Curiae 4-6.
To the extent that law enforcement still has specific concerns about the potential loss of evidence in a particular case, there remain more targeted ways to address those concerns. If "the police are truly confronted with a 'now or never' situation,"-for example, circumstances suggesting that a defendant's phone will be the target of an imminent remote-wipe attempt-they may be able to rely on exigent circumstances to search the phone immediately. Missouri v. McNeely, 569 U.S. ----, ----, 133 S.Ct. 1552, 1561-1562, 185 L.Ed.2d 696 (2013) (quoting Roaden v. Kentucky, 413 U.S. 496, 505, 93 S.Ct. 2796, 37 L.Ed.2d 757 (1973); some internal quotation marks omitted). Or, if officers happen to seize a phone in an unlocked state, they may be able to disable a phone's automatic-lock feature in order to prevent the phone from locking and encrypting data. See App. to Reply Brief in No. 13-132, p. 3a (diagramming the few necessary steps). Such a preventive measure could be analyzed under the principles set forth in our decision in McArthur, 531 U.S. 326, 121 S.Ct. 946, which approved officers' reasonable steps to secure a scene to preserve evidence while they awaited a warrant. See id., at 331-333, 121 S.Ct. 946.
B
The search incident to arrest exception rests not only on the heightened government interests at stake in a volatile arrest situation, but also on an arrestee's reduced privacy interests upon being taken into police custody. Robinson focused primarily on the first of those rationales. But it also quoted with approval then-Judge Cardozo's account of the historical basis for the search incident to arrest exception: "Search of the person becomes lawful when grounds for arrest and accusation have been discovered, and the law is in the act of subjecting the body of the accused to its physical dominion." 414 U.S., at 232, 94 S.Ct. 467 (quoting People v. Chiagles, 237 N.Y. 193, 197, 142 N.E. 583, 584 (1923)); see also 414 U.S., at 237, 94 S.Ct. 467 (Powell, J., concurring) ("an individual lawfully subjected to a custodial arrest retains no significant Fourth Amendment interest in the privacy of his person"). Put simply, a patdown of Robinson's clothing and an inspection of the cigarette pack found in his pocket constituted only minor additional intrusions compared to the substantial government authority exercised in taking Robinson into custody. See Chadwick, 433 U.S., at 16, n. 10, 97 S.Ct. 2476 (searches of a person are justified in part by "reduced expectations of privacy caused by the arrest").
The fact that an arrestee has diminished privacy interests does not mean that the Fourth Amendment falls out of the picture entirely. Not every search "is acceptable solely because a person is in custody." Maryland v. King, 569 U.S. ----, ----, 133 S.Ct. 1958, 1979, 186 L.Ed.2d 1 (2013). To the contrary, when "privacy-related concerns are weighty enough" a "search may require a warrant, notwithstanding the diminished expectations of privacy of the arrestee." Ibid. One such example, of course, is Chimel.Chimel refused to "characteriz[e] the invasion of privacy that results from a top-to-bottom search of a man's house as'minor.' " 395 U.S., at 766-767, n. 12, 89 S.Ct. 2034. Because a search of the arrestee's entire house was a substantial invasion beyond the arrest itself, the Court concluded that a warrant was required.
Robinson is the only decision from this Court applying Chimel to a search of the contents of an item found on an arrestee's person. In an earlier case, this Court had approved a search of a zipper bag carried by an arrestee, but the Court analyzed only the validity of the arrest itself. See Draper v. United States, 358 U.S. 307, 310-311, 79 S.Ct. 329, 3 L.Ed.2d 327 (1959). Lower courts applying Robinson and Chimel, however, have approved searches of a variety of personal items carried by an arrestee. See, e.g., United States v. Carrion, 809 F.2d 1120, 1123, 1128 (C.A.5 1987) (billfold and address book); United States v. Watson, 669 F.2d 1374, 1383-1384 (C.A.11 1982) (wallet); United States v. Lee, 501 F.2d 890, 892 (C.A.D.C.1974) (purse).
The United States asserts that a search of all data stored on a cell phone is "materially indistinguishable" from searches of these sorts of physical items. Brief for United States in No. 13-212, p. 26. That is like saying a ride on horseback is materially indistinguishable from a flight to the moon. Both are ways of getting from point A to point B, but little else justifies lumping them together. Modern cell phones, as a category, implicate privacy concerns far beyond those implicated by the search of a cigarette pack, a wallet, or a purse. A conclusion that inspecting the contents of an arrestee's pockets works no substantial additional intrusion on privacy beyond the arrest itself may make sense as applied to physical items, but any extension of that reasoning to digital data has to rest on its own bottom.
1
Cell phones differ in both a quantitative and a qualitative sense from other objects that might be kept on an arrestee's person. The term "cell phone" is itself misleading shorthand; many of these devices are in fact minicomputers that also happen to have the capacity to be used as a telephone. They could just as easily be called cameras, video players, rolodexes, calendars, tape recorders, libraries, diaries, albums, televisions, maps, or newspapers.
One of the most notable distinguishing features of modern cell phones is their immense storage capacity. Before cell phones, a search of a person was limited by physical realities and tended as a general matter to constitute only a narrow intrusion on privacy. See Kerr, Foreword: Accounting for Technological Change, 36 Harv. J.L. & Pub. Pol'y 403, 404-405 (2013). Most people cannot lug around every piece of mail they have received for the past several months, every picture they have taken, or every book or article they have read-nor would they have any reason to attempt to do so. And if they did, they would have to drag behind them a trunk of the sort held to require a search warrant in Chadwick,supra, rather than a container the size of the cigarette package in Robinson.
But the possible intrusion on privacy is not physically limited in the same way when it comes to cell phones. The current top-selling smart phone has a standard capacity of 16 gigabytes (and is available with up to 64 gigabytes). Sixteen gigabytes translates to millions of pages of text, thousands of pictures, or hundreds of videos. See Kerr, supra, at 404; Brief for Center for Democracy & Technology et al. as Amici Curiae 7-8. Cell phones couple that capacity with the ability to store many different types of information: Even the most basic phones that sell for less than $20 might hold photographs, picture messages, text messages, Internet browsing history, a calendar, a thousand-entry phone book, and so on. See id., at 30; United States v. Flores-Lopez, 670 F.3d 803, 806 (C.A.7 2012). We expect that the gulf between physical practicability and digital capacity will only continue to widen in the future.
The storage capacity of cell phones has several

Question: What is the issue area of the decision?
A. Criminal Procedure
B. Civil Rights
C. First Amendment
D. Due Process
E. Privacy
F. Attorneys
G. Unions
H. Economic Activity
I. Judicial Power
J. Federalism
K. Interstate Relations
L. Federal Taxation
M. Miscellaneous
N. Private Action
Answer:

Answer: A