Source: https://caselaw.findlaw.com/us-supreme-court/13-132.html
Timestamp: 2020-01-28 00:16:28
Document Index: 785209318

Matched Legal Cases: ['art, 547', '§5', '§7', '§7', '§2510', '§5']

RILEY v. CALIFORNIA | FindLaw
Argued: April 29, 2014Decided: July 21, 2014
(a) A warrantless search is reasonable only if it falls within a specific exception to the Fourth Amendment's warrant requirement. See Kentucky v. King, 563 U. S. ___, ___. The well-established exception at issue here applies when a warrantless search is conducted incident to a lawful arrest.
(ii) The United States and California raise concerns about the destruction of evidence, arguing that, even if the cell phone is physically secure, information on the cell phone remains vulnerable to remote wiping and data encryption. As an initial matter, those broad concerns are distinct from Chimel's focus on a defendant who responds to arrest by trying to conceal or destroy evidence within his reach. The briefing also gives little indication that either problem is prevalent or that the opportunity to perform a search incident to arrest would be an effective solution. And, at least as to remote wiping, law enforcement currently has some technologies of its own for combatting the loss of evidence. Finally, law enforcement's remaining concerns in a particular case might be addressed by responding in a targeted manner to urgent threats of remote wiping, see Missouri v. McNeely, 569 U. S. ___, ___, or by taking action to disable a phone's locking mechanism in order to secure the scene, see Illinois v. McArthur, 531 U. S. 326, 331-333. Pp. 12-15.
(i) Cell phones differ in both a quantitative and a qualitative sense from other objects that might be carried on an arrestee's person. Notably, modern cell phones have an immense storage capacity. Before cell phones, a search of a person was limited by physical realities and generally constituted only a narrow intrusion on privacy. But cell phones can store millions of pages of text, thousands of pictures, or hundreds of videos. This has several interrelated privacy consequences. First, a cell phone collects in one place many distinct types of information that reveal much more in combination than any isolated record. Second, the phone's capacity allows even just one type of information to convey far more than previously possible. Third, data on the phone can date back for years. In addition, an element of pervasiveness characterizes cell phones but not physical records. A decade ago officers might have occasionally stumbled across a highly personal item such as a diary, but today many of the more than 90% of American adults who own cell phones keep on their person a digital record of nearly every aspect of their lives. Pp. 17-21.
DAVID LEON RILEY, PETITIONER 13-132 v. CALIFORNIA UNITED STATES, PETITIONER 13-212 v. BRIMA WURIE
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.
As the text makes clear, "the ultimate touchstone of the Fourth Amendment is 'reasonableness.' " Brigham City v. Stuart, 547 U. S. 398, 403 (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 (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 (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. ___, ___ (2011) (slip op., at 5-6).
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. 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).
"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.
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. 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 (1977) (200-pound, locked footlocker could not be searched incident to arrest), abrogated on other grounds by California v. Acevedo, 500 U. S. 565 (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. 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. 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 (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.
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.
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.
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.
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. And any such threats from outside the arrest scene do not "lurk[ ] in all custodial arrests." Chadwick, 433 U. S., at 14-15. 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 (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.").
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.
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. ___, ___ (2013) (slip op., at 10) (quoting Roaden v. Kentucky, 413 U. S. 496, 505 (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, which approved officers' reasonable steps to secure a scene to preserve evidence while they awaited a warrant. See id., at 331-333.
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 (quoting People v. Chiagles, 237 N. Y. 193, 197, 142 N. E. 583, 584 (1923)); see also 414 U. S., at 237 (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 cloth-ing 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 (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. ___, ___ (2013) (slip op., at 26). 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. 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.
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.
The storage capacity of cell phones has several interrelated consequences for privacy. First, a cell phone collects in one place many distinct types of information--an address, a note, a prescription, a bank statement, a video--that reveal much more in combination than any isolated record. Second, a cell phone's capacity allows even just one type of information to convey far more than previously possible. The sum of an individual's private life can be reconstructed through a thousand photographs labeled with dates, locations, and descriptions; the same cannot be said of a photograph or two of loved ones tucked into a wallet. Third, the data on a phone can date back to the purchase of the phone, or even earlier. A person might carry in his pocket a slip of paper reminding him to call Mr. Jones; he would not carry a record of all his communications with Mr. Jones for the past several months, as would routinely be kept on a phone.1
Finally, there is an element of pervasiveness that characterizes cell phones but not physical records. Prior to the digital age, people did not typically carry a cache of sensitive personal information with them as they went about their day. Now it is the person who is not carrying a cell phone, with all that it contains, who is the exception. According to one poll, nearly three-quarters of smart phone users report being within five feet of their phones most of the time, with 12% admitting that they even use their phones in the shower. See Harris Interactive, 2013 Mobile Consumer Habits Study (June 2013). A decade ago police officers searching an arrestee might have occasionally stumbled across a highly personal item such as a diary. See, e.g., United States v. Frankenberry, 387 F. 2d 337 (CA2 1967) (per curiam). But those discoveries were likely to be few and far between. Today, by contrast, it is no exaggeration to say that many of the more than 90% of American adults who own a cell phone keep on their person a digital record of nearly every aspect of their lives--from the mundane to the intimate. See Ontario v. Quon, 560 U. S. 746, 760 (2010). Allowing the police to scrutinize such records on a routine basis is quite different from allowing them to search a personal item or two in the occasional case.
Although the data stored on a cell phone is distinguished from physical records by quantity alone, certain types of data are also qualitatively different. An Internet search and browsing history, for example, can be found on an Internet-enabled phone and could reveal an individual's private interests or concerns--perhaps a search for certain symptoms of disease, coupled with frequent visits to WebMD. Data on a cell phone can also reveal where a person has been. Historic location information is a stand-ard feature on many smart phones and can reconstruct someone's specific movements down to the minute, not only around town but also within a particular building. See United States v. Jones, 565 U. S. ___, ___ (2012) (Sotomayor, J., concurring) (slip op., at 3) ("GPS monitoring generates a precise, comprehensive record of a person's public movements that reflects a wealth of detail about her familial, political, professional, religious, and sexual associations.").
In 1926, Learned Hand observed (in an opinion later quoted in Chimel) that it is "a totally different thing to search a man's pockets and use against him what they contain, from ransacking his house for everything which may incriminate him." United States v. Kirschenblatt, 16 F. 2d 202, 203 (CA2). If his pockets contain a cell phone, however, that is no longer true. Indeed, a cell phone search would typically expose to the government far more than the most exhaustive search of a house: A phone not only contains in digital form many sensitive records previ-ously found in the home; it also contains a broad array of private information never found in a home in any form--unless the phone is.
To further complicate the scope of the privacy interests at stake, the data a user views on many modern cell phones may not in fact be stored on the device itself. Treating a cell phone as a container whose contents may be searched incident to an arrest is a bit strained as an initial matter. See New York v. Belton, 453 U. S. 454, 460, n. 4 (1981) (describing a "container" as "any object capable of holding another object"). But the analogy crumbles entirely when a cell phone is used to access data located elsewhere, at the tap of a screen. That is what cell phones, with increasing frequency, are designed to do by taking advantage of "cloud computing." Cloud computing is the capacity of Internet-connected devices to display data stored on remote servers rather than on the device itself. Cell phone users often may not know whether particular information is stored on the device or in the cloud, and it generally makes little difference. See Brief for Electronic Privacy Information Center in No. 13-132, at 12-14, 20. Moreover, the same type of data may be stored locally on the device for one user and in the cloud for another.
The United States concedes that the search incident to arrest exception may not be stretched to cover a search of files accessed remotely--that is, a search of files stored in the cloud. See Brief for United States in No. 13-212, at 43-44. Such a search would be like finding a key in a suspect's pocket and arguing that it allowed law enforcement to unlock and search a house. But officers searching a phone's data would not typically know whether the information they are viewing was stored locally at the time of the arrest or has been pulled from the cloud.
Although the Government recognizes the problem, its proposed solutions are unclear. It suggests that officers could disconnect a phone from the network before searching the device--the very solution whose feasibility it contested with respect to the threat of remote wiping. Compare Tr. of Oral Arg. in No. 13-132, at 50-51, with Tr. of Oral Arg. in No. 13-212, pp. 13-14. Alternatively, the Government proposes that law enforcement agencies "develop protocols to address" concerns raised by cloud computing. Reply Brief in No. 13-212, pp. 14-15. Probably a good idea, but the Founders did not fight a revolution to gain the right to government agency protocols. The possibility that a search might extend well beyond papers and effects in the physical proximity of an arrestee is yet another reason that the privacy interests here dwarf those in Robinson.
Apart from their arguments for a direct extension of Robinson, the United States and California offer various fallback options for permitting warrantless cell phone searches under certain circumstances. Each of the proposals is flawed and contravenes our general preference to provide clear guidance to law enforcement through categorical rules. "[I]f police are to have workable rules, the balancing of the competing interests . . . 'must in large part be done on a categorical basis--not in an ad hoc, case-by-case fashion by individual police officers.' " Michigan v. Summers, 452 U. S. 692, 705, n. 19 (1981) (quoting Dunaway v. New York, 442 U. S. 200, 219-220 (1979) (White, J., concurring)).
The United States first proposes that the Gant standard be imported from the vehicle context, allowing a warrantless search of an arrestee's cell phone whenever it is reasonable to believe that the phone contains evidence of the crime of arrest. But Gant relied on "circumstances unique to the vehicle context" to endorse a search solely for the purpose of gathering evidence. 556 U. S., at 343. Justice Scalia's Thornton opinion, on which Gant was based, explained that those unique circumstances are "a reduced expectation of privacy" and "heightened law enforcement needs" when it comes to motor vehicles. 541 U. S., at 631; see also Wyoming v. Houghton, 526 U. S., at 303-304. For reasons that we have explained, cell phone searches bear neither of those characteristics.
At any rate, a Gant standard would prove no practical limit at all when it comes to cell phone searches. In the vehicle context, Gant generally protects against searches for evidence of past crimes. See 3 W. LaFave, Search and Seizure §7.1(d), at 709, and n. 191. In the cell phone context, however, it is reasonable to expect that incriminating information will be found on a phone regardless of when the crime occurred. Similarly, in the vehicle context Gant restricts broad searches resulting from minor crimes such as traffic violations. See id., §7.1(d), at 713, and n. 204. That would not necessarily be true for cell phones. It would be a particularly inexperienced or unimaginative law enforcement officer who could not come up with several reasons to suppose evidence of just about any crime could be found on a cell phone. Even an individual pulled over for something as basic as speeding might well have locational data dispositive of guilt on his phone. An individual pulled over for reckless driving might have evidence on the phone that shows whether he was texting while driving. The sources of potential pertinent information are virtually unlimited, so applying the Gant standard to cell phones would in effect give "police officers unbridled discretion to rummage at will among a person's private effects." 556 U. S., at 345.
Finally, at oral argument California suggested a different limiting principle, under which officers could search cell phone data if they could have obtained the same information from a pre-digital counterpart. See Tr. of Oral Arg. in No. 13-132, at 38-43; see also Flores-Lopez, 670 F. 3d, at 807 ("If police are entitled to open a pocket diary to copy the owner's address, they should be entitled to turn on a cell phone to learn its number."). But the fact that a search in the pre-digital era could have turned up a photograph or two in a wallet does not justify a search of thousands of photos in a digital gallery. The fact that someone could have tucked a paper bank statement in a pocket does not justify a search of every bank statement from the last five years. And to make matters worse, such an analogue test would allow law enforcement to search a range of items contained on a phone, even though people would be unlikely to carry such a variety of information in physical form. In Riley's case, for example, it is implausible that he would have strolled around with video tapes, photo albums, and an address book all crammed into his pockets. But because each of those items has a pre-digital analogue, police under California's proposal would be able to search a phone for all of those items--a significant diminution of privacy.
In addition, an analogue test would launch courts on a difficult line-drawing expedition to determine which digital files are comparable to physical records. Is an e-mail equivalent to a letter? Is a voicemail equivalent to a phone message slip? It is not clear how officers could make these kinds of decisions before conducting a search, or how courts would apply the proposed rule after the fact. An analogue test would "keep defendants and judges guessing for years to come." Sykes v. United States, 564 U. S. 1, ___ (2011) (Scalia, J., dissenting) (slip op., at 7) (discussing the Court's analogue test under the Armed Career Criminal Act).
Our holding, of course, is not that the information on a cell phone is immune from search; it is instead that a warrant is generally required before such a search, even when a cell phone is seized incident to arrest. Our cases have historically recognized that the warrant requirement is "an important working part of our machinery of gov-ernment," not merely "an inconvenience to be somehow 'weighed' against the claims of police efficiency." Coolidge v. New Hampshire, 403 U. S. 443, 481 (1971). Recent technological advances similar to those discussed here have, in addition, made the process of obtaining a warrant itself more efficient. See McNeely, 569 U. S., at ___ (slip op., at 11-12); id., at ___ (Roberts, C. J., concurring in part and dissenting in part) (slip op., at 8) (describing jurisdiction where "police officers can e-mail warrant requests to judges' iPads [and] judges have signed such warrants and e-mailed them back to officers in less than 15 minutes").
Moreover, even though the search incident to arrest exception does not apply to cell phones, other case-specific exceptions may still justify a warrantless search of a particular phone. "One well-recognized exception applies when ' "the exigencies of the situation" make the needs of law enforcement so compelling that [a] warrantless search is objectively reasonable under the Fourth Amendment.' " Kentucky v. King, 563 U. S., at ___ (slip op., at 6) (quoting Mincey v. Arizona, 437 U. S. 385, 394 (1978)). Such exigencies could include the need to prevent the imminent destruction of evidence in individual cases, to pursue a fleeing suspect, and to assist persons who are seriously injured or are threatened with imminent injury. 563 U. S., at ___. In Chadwick, for example, the Court held that the exception for searches incident to arrest did not justify a search of the trunk at issue, but noted that "if officers have reason to believe that luggage contains some immediately dangerous instrumentality, such as explosives, it would be foolhardy to transport it to the station house without opening the luggage." 433 U. S., at 15, n. 9.
In light of the availability of the exigent circumstances exception, there is no reason to believe that law enforcement officers will not be able to address some of the more extreme hypotheticals that have been suggested: a suspect texting an accomplice who, it is feared, is preparing to detonate a bomb, or a child abductor who may have information about the child's location on his cell phone. The defendants here recognize--indeed, they stress--that such fact-specific threats may justify a warrantless search of cell phone data. See Reply Brief in No. 13-132, at 8-9; Brief for Respondent in No. 13-212, at 30, 41. The critical point is that, unlike the search incident to arrest exception, the exigent circumstances exception requires a court to examine whether an emergency justified a warrantless search in each particular case. See McNeely, supra, at ___ (slip op., at 6).2
Our cases have recognized that the Fourth Amendment was the founding generation's response to the reviled "general warrants" and "writs of assistance" of the colonial era, which allowed British officers to rummage through homes in an unrestrained search for evidence of criminal activity. Opposition to such searches was in fact one of the driving forces behind the Revolution itself. In 1761, the patriot James Otis delivered a speech in Boston denouncing the use of writs of assistance. A young John Adams was there, and he would later write that "[e]very man of a crowded audience appeared to me to go away, as I did, ready to take arms against writs of assistance." 10 Works of John Adams 247-248 (C. Adams ed. 1856). According to Adams, Otis's speech was "the first scene of the first act of opposition to the arbitrary claims of Great Britain. Then and there the child Independence was born." Id., at 248 (quoted in Boyd v. United States, 116 U. S. 616, 625 (1886)).
Modern cell phones are not just another technological convenience. With all they contain and all they may reveal, they hold for many Americans "the privacies of life," Boyd, supra, at 630. The fact that technology now allows an individual to carry such information in his hand does not make the information any less worthy of the protection for which the Founders fought. Our answer to the question of what police must do before searching a cell phone seized incident to an arrest is accordingly simple--get a warrant.
First, I am not convinced at this time that the ancient rule on searches incident to arrest is based exclusively (or even primarily) on the need to protect the safety of arresting officers and the need to prevent the destruction of evidence. Cf. ante, at 9. This rule antedates the adoption of the Fourth Amendment by at least a century. See T. Clancy, The Fourth Amendment: Its History and Interpretation 340 (2008); T. Taylor, Two Studies in Constitutional Interpretation 28 (1969); Amar, Fourth Amendment First Principles, 107 Harv. L. Rev. 757, 764 (1994). In Weeks v. United States, 232 U. S. 383, 392 (1914), we held that the Fourth Amendment did not disturb this rule. See also Taylor, supra, at 45; Stuntz, The Substantive Origins of Criminal Procedure, 105 Yale L. J. 393, 401 (1995) ("The power to search incident to arrest--a search of the arrested suspect's person . . .--was well established in the mid-eighteenth century, and nothing in . . . the Fourth Amendment changed that"). And neither in Weeks nor in any of the authorities discussing the old common-law rule have I found any suggestion that it was based exclusively or primarily on the need to protect arresting officers or to prevent the destruction of evidence.
What ultimately convinces me that the rule is not closely linked to the need for officer safety and evidence preservation is that these rationales fail to explain the rule's well-recognized scope. It has long been accepted that written items found on the person of an arrestee may be examined and used at trial.* But once these items are taken away from an arrestee (something that obviously must be done before the items are read), there is no risk that the arrestee will destroy them. Nor is there any risk that leaving these items unread will endanger the arresting officers.
The regulation of electronic surveillance provides an instructive example. After this Court held that electronic surveillance constitutes a search even when no property interest is invaded, see Katz v. United States, 389 U. S. 347, 353-359 (1967), Congress responded by enacting Title III of the Omnibus Crime Control and Safe Streets Act of 1968, 82 Stat. 211. See also 18 U. S. C. §2510 et seq. Since that time, electronic surveillance has been governed primarily, not by decisions of this Court, but by the stat-ute, which authorizes but imposes detailed restrictions on electronic surveillance. See ibid.
In Wurie's case, for example, the dissenting First Circuit judge argued that exigent circumstances could have justified a search of Wurie's phone. See 728 F. 3d 1, 17 (2013) (opinion of Howard, J.) (discussing the repeated unanswered calls from "my house," the suspected location of a drug stash). But the majority concluded that the Government had not made an exigent circumstances argument. See id., at 1. The Government acknowledges the same in this Court. See Brief for United States in No. 13-212, p. 28, n. 8.
* Cf. Hill v. California, 401 U. S. 797, 799-802, and n. 1 (1971) (diary); Marron v. United States, 275 U. S. 192, 193, 198-199 (1927) (ledger and bills); Gouled v. United States, 255 U. S. 298, 309 (1921), overruled on other grounds, Warden, Md. Penitentiary v. Hayden, 387 U. S. 294, 300-301 (1967) (papers); see United States v. Rodriguez, 995 F. 2d 776, 778 (CA7 1993) (address book); United States v. Armendariz-Mata, 949 F. 2d 151, 153 (CA5 1991) (notebook); United States v. Molinaro, 877 F. 2d 1341 (CA7 1989) (wallet); United States v. Richardson, 764 F. 2d 1514, 1527 (CA11 1985) (wallet and papers); United States v. Watson, 669 F. 2d 1374, 1383-1384 (CA11 1982) (documents found in a wallet); United States v. Castro, 596 F. 2d 674, 677 (CA5 1979), cert. denied, 444 U. S. 963 (1979) (paper found in a pocket); United States v. Jeffers, 520 F. 2d 1256, 1267-1268 (CA7 1975) (three notebooks and meeting minutes); Bozel v. Hudspeth, 126 F. 2d 585, 587 (CA10 1942) (papers, circulars, advertising matter, "memoranda containing various names and addresses"); United States v. Park Avenue Pharmacy, 56 F. 2d 753, 755 (CA2 1932) ("numerous prescriptions blanks" and a check book). See also 3 W. LaFave, Search and Seizure §5.2(c), p. 144 (5th ed. 2012) ("Lower courts, in applying Robinson, have deemed evidentiary searches of an arrested person to be virtually unlimited"); W. Cuddihy, Fourth Amendment: Origins and Original Meaning 847-848 (1990) (in the pre-Constitution colonial era, "[a]nyone arrested could expect that not only his surface clothing but his body, luggage, and saddlebags would be searched").