Opinion ID: 2823553
Heading Depth: 1
Heading Rank: 3

Heading: C.4 infra.

Text: In United States v. Skinner, 690 F.3d 772 (6th Cir. 2012), the Sixth Circuit held that the defendant “did not have a reasonable expectation of privacy in the data given off by his voluntarily procured pay-as-you-go cell phone.” 690 F.3d at 777. This case involved locational surveillance of two cell phones in real time over the course of a few days as the users (Continued) 30 specifically cited “[h]istoric location information” as among the heightened privacy concerns presented in government inspection of cell phones, as such information details the user’s “specific movements down to the minute, not only around town but also within a particular building.” 134 S. Ct. at 2490. 7 Taken together, Karo, Kyllo, and the views expressed in Riley and the Jones concurrences support our conclusion that the government invades a reasonable expectation of privacy when it relies upon technology not in general use to discover the movements of an individual over an extended period of time. Cell phone tracking through inspection of CSLI is one such technology. It is possible that the CSLI for a particular cell transported marijuana along public roads. Id. at 776. The Sixth Circuit determined that the case was governed by Knotts, id. at 777-78, and distinguished Jones based on the “comprehensiveness of the tracking” in that case, involving “‘constant monitoring’” over the course of four weeks, id. at 780 (quoting Jones, 132 S. Ct. at 963 (Alito, J., concurring in the judgment)). The instant case is similarly distinguishable. 7Some courts, including the district court in this case, as well as the dissent, have suggested that privacy interests in real-time or prospective location information are greater than those in historical location information, like that at issue in this case. See (Quartavious) Davis, 785 F.3d at 509 n.10; Graham, 846 F. Supp. 2d at 391. We see no constitutional distinction between the two types of data. A person’s expectation of privacy in information about where she has been is no less reasonable, or less deserving of respect, than that regarding where she is or where she is going. 31 phone is not very revealing at all because, for instance, the phone has been turned off or it has made few or no connections to the cellular network. But the government cannot know in advance of obtaining this information how revealing it will be or whether it will detail the cell phone user’s movements in private spaces. See Earls, 70 A.3d at 642. We hold, therefore, that the government engages in a Fourth Amendment search when it seeks to examine historical CSLI pertaining to an extended time period like 14 or 221 days. 8 3. The district court concluded that this case is distinguishable from Karo and Maynard/Jones because the type of locational surveillance at issue in those cases permits realtime tracking with greater precision and continuity than the examination of historical CSLI. See Graham, 846 F. Supp. 2d at 391-92, 404. The use of GPS technology challenged in Maynard/Jones permitted law enforcement to track the suspect’s vehicle continuously at every moment “‘24 hours a day for 28 days[,]’” id. at 392 (quoting Maynard, 615 F.3d at 558), while, 8This case does not require us to draw a bright line as to how long the time period for historical CSLI can be before its inspection rises to the level of a Fourth Amendment search, and we decline to do so. 32 here, the CSLI records only disclose a finite number of location data points for certain points in time. This distinction is constitutionally insignificant. The Fourth Amendment challenge is directed toward the government’s investigative conduct, i.e., its decision to seek and inspect CSLI records without a warrant. There is no way the government could have known before obtaining the CSLI records how granular the location data in the records would be. If Appellants had been in constant use of their phones as they moved about each waking day – constantly starting and terminating calls – then the government would have obtained a continuous stream of historical location information approaching that of GPS. A similar or greater degree of continuity would have been achieved if Appellants had smartphones that automatically connect to the nearest cell site every few minutes or seconds. As it turns out, the CSLI records did reveal an impressive 29,659 location data points for Graham and 28,410 for Jordan, amounting to well over 100 data points for each Appellant per day on average. This quantum of data is substantial enough to provide a reasonably detailed account of Appellants’ movements during the 221-day time period, including movements to and from the cell-site sectors in which their homes were located. We therefore reject the district court’s suggestion that the CSLI 33 was not sufficiently continuous to raise reasonable privacy concerns. The district court also questioned the precision of the location data itself, concluding that the CSLI did not identify sufficiently precise locations to invade a reasonable privacy expectation. Unlike GPS data, the court found, CSLI “can only reveal the general vicinity in which a cellular phone is used.” Graham, 846 F. Supp. 2d at 392. The precision of CSLI in identifying the location of a cell phone depends in part on the size of the coverage area associated with each cell-site sector listed in the records. 9 Service providers have begun to increase network capacity and to fill gaps in network coverage by installing low-power cells such as “microcells” and “femtocells,” which cover areas as small as 40 feet. 10 The intense competition among cellular networks 9 Sprint/Nextel’s custodian testified at trial that the cell sites listed in the records each had, at most, a two-mile radius of operability. Each cell site, therefore, covered no greater than approximately 12.6 square miles, divided into three sectors of approximately 4.2 square miles or less. 10 See Federal Communications Commission, Public Safety Tech Topic #23 – Femtocells, http://www.fcc.gov/help/public-safetytech-topic-23-femtocells; PR Newswire, Small Cells Market 20142019: Femtocell, Picocell, & Microcell Prospects for LTE, SONs, Wireless Offloading & Heterogeneous Networks (Nov. 6, 2014), http://www.prnewswire.com/news-releases/small-cells-market-20142019-femtocell-picocell--microcell-prospects-for-lte-sonswireless-offloading--heterogeneous-networks-281857341.html; Nancy Gohring, Femtocells Make Way Into Enterprises, (Continued) 34 provides ample reason to anticipate increasing use of small cells and, as a result, CSLI of increasing precision. We must take such developments into account. See Kyllo, 533 U.S. at 36 (“While the technology used in the present case was relatively crude, the rule we adopt must take account of more sophisticated systems that are already in use or in development.”). In any event, the CSLI at issue here was precise enough, at minimum, to support reasonable inferences about Appellants’ locations at specific points in time. Otherwise, the information would have lacked any probative value at trial. The very reason that the government obtained and introduced the evidence was to establish Appellants’ locations during times surrounding the charged robberies. 11 Investigators and prosecutors must have ComputerWorld (May 7, 2011), http://www.computerworld.com/article/2550032/mobilewireless/femtocells-make-way-into-enterprises.html. 11Specifically, the government used the CSLI to show, among other things, that Graham was within a few miles of the Dollar Tree before and after the robbery of January 17, 2011; Graham was within a few miles of the 7-Eleven before and after the robbery of January 22, 2011; minutes after the robbery of Shell on February 1, 2011, Jordan was near the Shell and then both he and Graham were near Jordan’s apartment; Appellants were both near Jordan’s apartment approximately 45 minutes before robbery of Burger King on February 5, 2011; Graham was near the Burger King within minutes of the robbery; Appellants were together a few miles north of the Burger King minutes after the robbery; and Graham was near the McDonald’s approximately one half hour before the McDonald’s robbery. 35 believed, after analyzing the CSLI, that it was sufficiently precise to establish Appellants’ whereabouts. The fact that inference was required to glean Appellants’ past locations from the CSLI does not ameliorate or lessen in any manner the invasion of privacy. Indeed, the Supreme Court, in Kyllo, specifically rejected “the novel proposition that inference insulates a search . . . .” Id. at 36 (citing Karo, 468 U.S. 705). We therefore reject the government’s argument that the CSLI was not adequately precise to infringe upon Appellants’ expectations of privacy in their locations and movements. 4. We also disagree with the district court’s and the dissent’s conclusion that Appellants lacked a reasonable expectation of privacy in their CSLI because the CSLI records were kept by Sprint/Nextel in the ordinary course of business. See Graham, 846 F. Supp. 2d at 403; post at 111. The dissent argues first that “[t]he nature of the governmental activity” at issue in this case sets it apart from Karo, Kyllo, and Jones. Post at 108-09. While Karo, Kyllo, and Jones each involved direct and contemporaneous surveillance by government agents, the locational tracking challenged here was achieved through government inspection of records held by a third party. 36 This distinction is inconsequential. The precedents of this Court and others show that a Fourth Amendment search may certainly be achieved through an inspection of third-party records. See, e.g., Doe v. Broderick, 225 F.3d 440, 450-52 (4th Cir. 2000) (holding that detective’s examination of a patient file held by a methadone clinic was a search and, without probable cause, violated the patient’s Fourth Amendment rights); DeMassa v. Nunez, 770 F.2d 1505, 1508 (9th Cir. 1985) (holding that “an attorney’s clients have a legitimate expectation of privacy in their client files”); cf. Ferguson v. City of Charleston, 532 U.S. 67, 78 (2001) (holding that patients enjoy a reasonable expectation of privacy that the results of diagnostic tests will not be disclosed to law enforcement without the patient’s consent). 12 That the government acquired 12 In the sense most crucial to a proper Fourth Amendment analysis, “[t]he nature of the governmental activity” challenged in this case, post at 108-09, was not unlike that challenged in Karo, Kyllo, and Jones. The dissent’s language is apparently drawn from Smith v. Maryland, 442 U.S. 735 (1979), where the Court deemed it important to identify “the nature of the state activity that is challenged” in order to determine the precise nature of Smith’s Fourth Amendment claim. 442 U.S. at 741. Specifically, this initial inquiry was made in order to determine whether Smith could claim an invasion of his property or intrusion into a constitutionally protected area, under the traditional trespass-based theory of Fourth Amendment protection. Because the challenged governmental activity was the installation of a pen register “on telephone company property at the telephone company’s central offices,” Smith could make no such claim. Id. Instead, Smith claimed an invasion of a legitimate expectation of privacy in the numbers he dialed, (Continued) 37 Appellants’ private information through an inspection of thirdparty records cannot dispose of their Fourth Amendment claim. Yet the dissent seizes upon the fact that the government obtained Appellants’ CSLI from a third-party cell service provider and maintains that we have placed our focus on the wrong question. Instead of assessing the reasonableness of Appellants’ expectation of privacy in their “location and movements over time,” our dissenting colleague would frame the question as “whether an individual has a reasonable expectation which the government obtained through use of the pen register. Id. at 742. In this sense, the nature of the governmental activity challenged in this case is not unlike the activities challenged in Karo, Kyllo, and Jones. In Karo and Kyllo, the nature of the challenged governmental activity was the use of technology to acquire certain private information rather than the physical invasion of constitutionally protected property or spaces. See Karo, 468 U.S. at 714; Kyllo, 533 U.S. at 34-35. The governmental activity challenged in Jones was of both sorts: installation of a GPS tracking device effected through a trespass onto Jones’ property, and use of the device to obtain information about Jones’ location and movements over an extended period of time. As previously noted, the majority confined its analysis to the trespass without considering the nature of the information the government subsequently acquired. 132 S. Ct. at 949-54. In the concurrences, five Justices focused on the government’s acquisition of location information and whether this conduct invaded a legitimate expectation of privacy. Because the challenged activity in the present case, like those considered in Karo, Kyllo, and the Jones concurrences, is the government’s non-trespassory acquisition of certain information, our inquiry is properly focused on the legitimacy of Appellants’ expectation of privacy in this information. 38 of privacy in a third party’s records that permit the government to deduce this information.” Post at 109. But even the analyses in the cases upon which the dissent relies focused foremost on whether, under Katz, the privacy expectations asserted for certain information obtained by the government were legitimate. See United States v. Miller, 425 U.S. 435, 442 (1976) (“We must examine the nature of the particular documents sought to be protected in order to determine whether there is a legitimate ‘expectation of privacy’ concerning their contents.” (emphasis added)); Smith v. Maryland, 442 U.S. 735, 742 (1979) (“[P]etitioner’s argument that [the] installation and use [of a pen register] constituted a ‘search’ necessarily rests upon a claim that he had a ‘legitimate expectation of privacy’ regarding the numbers he dialed on his phone.” (emphasis added)). In answering that question, the fact that the information at issue in Miller and Smith was contained in records held by third parties became relevant only insofar as the defendant in each case had “voluntarily conveyed” the information to the third party in the first place. See Miller, 425 U.S. at 442; Smith, 442 U.S. at 743-44. It is clear to us, as explained below, that cell phone users do not voluntarily convey their CSLI to their service providers. The third-party doctrine of Miller and Smith is therefore inapplicable here. 39 a. The Supreme Court held in Miller and Smith that “a person has no legitimate expectation of privacy in information he voluntarily turns over to third parties.” Smith, 442 U.S. at 743-44; see also Miller, 425 U.S. at 442. This is so even if “the information is revealed on the assumption that it will be used only for a limited purpose and the confidence placed in the third party will not be betrayed.” Miller, 425 U.S. at 443. 13 In Miller, the government used defective subpoenas to obtain financial records from the defendant’s bank. 425 U.S. at 436. The Court determined first that the defendant could not claim an unconstitutional invasion of his “private papers” because he had neither ownership nor possession of the transactional records at issue. Id. at 440-41 (citation omitted). Next, the Court turned to the defendant’s claim that the government violated his privacy interests in the contents of 13This “third-party” doctrine finds its roots in cases involving consensual disclosures to informants or undercover government agents. See United States v. White, 401 U.S. 745, 751-752 (1971); Hoffa v. United States, 385 U.S. 293, 302-303 (1966); Lopez v. United States, 373 U.S. 427, 439 (1963). White, Hoffa, Lopez, and similar cases generally establish that a person who confides information about her illegal activities in another bears the risk that this information will be reported to law enforcement, see White, 401 U.S. at 752, and introduced as evidence against her, see Lopez, 373 U.S. at 439. Any expectation she holds that this information will be held in confidence is not one entitled to Fourth Amendment protection. See White, 401 U.S. at 749; Hoffa, 385 U.S. at 301. 40 the bank records. Id. at 442. Because such documents “contain only information voluntarily conveyed to the banks and exposed to their employees in the ordinary course of business,” the Court held that the depositor lacks “any legitimate expectation of privacy” in this information. Id. at 442. “[I]n revealing his affairs to another,” the defendant assumed the risk “that the information [would] be conveyed by that person to the Government.” Id. at 443. In Smith, a telephone company, at the request of police, utilized a pen register device to record the numbers dialed from the home phone of Michael Lee Smith, a man suspected of robbing a woman and then harassing her through anonymous phone calls. 442 U.S. at 737. Smith argued that the warrantless installation of the pen register was an unreasonable search. Id. at 737-38. The Court determined, first, that people generally understand that they must communicate the numbers they dial to the phone company and that the company has facilities for recording and storing this information permanently. Id. at 742. Even if Smith had an actual expectation of privacy in the numbers he dialed, this would not be a “legitimate” expectation because he “voluntarily conveyed” the numerical information to the phone company and “‘exposed’” the information to the company’s recording and storage equipment. Id. at 744. In so doing, Smith 41 “assumed the risk” that the company would disclose this information to law enforcement. Id. We recently applied the third-party doctrine of Miller and Smith in United States v. Bynum, 604 F.3d 161 (4th Cir. 2010), where the government served administrative subpoenas on a website operator to obtain a user’s account information. 604 F.3d at 162. Specifically, the government obtained the user’s name, email address, telephone number, and physical address, id. at 164, all information that the user entered on the website when he opened his account, id. at 162. Citing Smith, we determined that, in “voluntarily convey[ing] all this information” to the Internet company, the user “‘assumed the risk’” that this information would be revealed to law enforcement. Id. at 164 (quoting Smith, 442 U.S. at 744). The user, therefore, could not show that he had either an actual or an objectively reasonable expectation of privacy in this information. Id. These precedents do not categorically exclude third-party records from Fourth Amendment protection. They simply hold that a person can claim no legitimate expectation of privacy in information she voluntarily conveys to a third party. It is that voluntary conveyance – not the mere fact that the information winds up in the third party’s records – that demonstrates an assumption of risk of disclosure and therefore the lack of any 42 reasonable expectation of privacy. We decline to apply the third-party doctrine in the present case because a cell phone user does not “convey” CSLI to her service provider at all – voluntarily or otherwise – and therefore does not assume any risk of disclosure to law enforcement. 14 The service provider automatically generates CSLI in response to connections made between the cell phone and the provider’s network, with and without the user’s active participation. See Augustine, 4 N.E.3d at 862 (“CSLI is purely a function and product of cellular telephone technology, created by the provider’s system network at the time that a cellular telephone call connects to a cell site.”); id. at 863 14 At the outset of its argument that the third-party doctrine applies here, the dissent insists that Appellants “exposed” their CSLI to their service provider and therefore assumed the risk of disclosure to law enforcement. Post at 111. This “exposure” language is derived from Miller and Smith, but it is clear in each of those cases that any “exposure” of the information at issue to the third party’s employees or facilities occurred only through the defendant’s voluntary conveyance of that information to the third party. See Miller, 425 U.S. at 442 (noting that the financial information at issue had been “voluntarily conveyed to the banks and exposed to their employees in the ordinary course of business” (emphasis added)); Smith, 442 U.S. at 744 (“When he used his phone, petitioner voluntarily conveyed numerical information to the telephone company and ‘exposed’ that information to its equipment in the ordinary course of business.” (emphasis added)). The dissent goes on to argue that Appellants did indeed voluntarily convey the wealth of cell site location data points at issue here to their service provider by choosing generally to operate and carry their phones. We reject this contention. 43 (describing CSLI as “location-identifying by-product” of cell phone technology). “Unlike the bank records in Miller or the phone numbers dialed in Smith, cell-site data is neither tangible nor visible to a cell phone user.” In re Application of U.S. for Historical Cell Site Data, 747 F. Supp. 2d 827, 844 (S.D. Tex. 2010), vacated, 724 F.3d 600 (5th Cir. 2013). A user is not required to actively submit any location-identifying information when making a call or sending a message. Such information is rather “quietly and automatically calculated by the network, without unusual or overt intervention that might be detected by the target user.” Id. at 833. We cannot impute to a cell phone user the risk that information about her location created by her service provider will be disclosed to law enforcement when she herself has not actively disclosed this information. Notably, the CSLI at issue in this appeal details location information not only for those transmissions in which Appellants actively participated – i.e., messages or calls they made or answered – but also for messages and calls their phones received but they did not answer. When a cell phone receives a call or message and the user does not respond, the phone’s location is identified without any affirmative act by its user at all – much less, “voluntary conveyance.” See In re Application of U.S. for an Order Directing a Provider of Electronic Communication 44 Service to Disclose Records to the Government (In re Application (Third Circuit)), 620 F.3d 304, 317 (3d Cir. 2010) (“[W]hen a cell phone user receives a call, he hasn’t voluntarily exposed anything at all.”). We conclude, in agreement with the analysis of the Third Circuit in In re Application (Third Circuit) and that of several state supreme courts, that the third-party doctrine of Smith and Miller does not apply to CSLI generated by cell phone service providers. See id.; Augustine, 4 N.E.3d at 862-63; Tracey, 152 So.3d at 525; see also Earls, 70 A.3d at 641-42 (categorically rejecting third-party doctrine). b. The Fifth Circuit, in In re Application of U.S. for Historical Cell Site Data (In re Application (Fifth Circuit)), 724 F.3d 600 (5th Cir. 2013), and the en banc Eleventh Circuit in United States v. (Quartavious) Davis, 785 F.3d 498 (11th Cir. 2015), have reached the opposite conclusion. While acknowledging that the cell phone user “does not directly inform his service provider of the location of the nearest cell phone tower[,]” the Fifth Circuit decided that users voluntarily convey CSLI to their service providers through general use of their cell phones. In re Application (Fifth Circuit), 724 F.3d at 614. 15 In 15 In United States v. Guerrero, 768 F.3d 351 (5th Cir. 2014), the Fifth Circuit reaffirmed its holding in In re (Continued) 45 reaching this conclusion, the court relied on the proposition, advanced by the government, that “users know that they convey information about their location to their service providers when they make a call.” Id. at 612. The Eleventh Circuit followed suit, suggesting that because users are generally aware that their calls are connected through cell towers, their use of their phones amounts to voluntary conveyance of “their general location within that cell tower’s range[.]” (Quartavious) Davis, 785 F.3d at 511. We cannot accept the proposition that cell phone users volunteer to convey their location information simply by choosing to activate and use their cell phones and to carry the devices on their person. Cell phone use is not only ubiquitous in our society today but, at least for an increasing portion of our society, it has become essential to full cultural and economic participation. See Quon, 560 U.S. at 760 (“Cell phone and text message communications are so pervasive that some persons may consider them to be essential means or necessary instruments for self-expression, even self-identification.”); Riley, 134 S. Ct. at 2484 (“[M]odern cell phones . . . are now such a pervasive and insistent part of daily life that the Application (Fifth Circuit) in affirming denial of a motion to suppress CSLI evidence. See 768 F.3d at 358-61. 46 proverbial visitor from Mars might conclude they were an important feature of human anatomy.”). People cannot be deemed to have volunteered to forfeit expectations of privacy by simply seeking active participation in society through use of their cell phones. “The fiction that the vast majority of the American population consents to warrantless government access to the records of a significant share of their movements by ‘choosing’ to carry a cell phone must be rejected.” In re Application (E.D.N.Y.), 809 F. Supp. 2d at 127, quoted in Tracey, 152 So.3d at 523. 16 16The dissent points out that similar arguments were made in dissenting opinions in Miller and Smith and ultimately rejected by the Court. We do not doubt that the financial services implicated in Miller or the telephone service implicated in Smith were any less crucial to social and economic participation than cell phone service has become. But the determination in each of those cases that the defendant had assumed the risk of disclosure to law enforcement did not rely upon the defendant’s general choice to avail himself of these services. The assumption of risk was based on voluntary acts by which the defendant conveyed specific information to a third party while using these services. Smith, for instance, actively and voluntarily turned specific numbers over to his phone company, and was surely aware of what numbers he was turning over, when he placed specific calls. See Smith, 442 U.S. at 742. Smith even conceded that he could claim no legitimate expectation of privacy in the same numbers had he placed the calls through a live operator. Id. at 744. Similarly here, we do not believe that Appellants could claim a legitimate privacy expectation had they specifically identified their location or the closest cell tower to their service provider each time a transmission was made to or from their cell phones. 47 Users’ understanding of how cellular networks generally function is beside the point. The more pertinent question is whether users are generally aware of what specific cell sites are utilized when their phones connect to a cellular network. After all, it is the specificity with which CSLI identifies cell sites that allows users’ location to be tracked and raises privacy concerns. We have no reason to suppose that users generally know what cell sites transmit their communications or where those cell sites are located. A cell phone user cannot be said to “voluntarily convey” to her service provider information that she never held but was instead generated by the service provider itself without the user’s involvement. 17 Both the Fifth and Eleventh Circuits emphasized that service providers maintain CSLI records for their own business purposes rather than for law enforcement purposes and on this basis concluded that a subscriber can have no legitimate privacy 17 In (Quartavious) Davis, the Eleventh Circuit pointed out that the pen register information at issue in Smith had the effect of disclosing precise information about the phone user’s location. 724 F.3d at 511-12. Pen register information could be used to place the phone user at a specific address at a specific time “because the phone lines at issue in Smith corresponded to stationary landlines at known physical addresses.” Id. The location information at issue in the present case is not “stationary” but permits tracking of a person’s movements across private and public spaces. In this way, CSLI raises greater locational privacy concerns than any location information revealed through use of a stationary landline. See Karo, 468 U.S. at 715. 48 expectation in the information these records contain. See In re Application (Fifth Circuit), 724 F.3d at 611-12; (Quartavious) Davis, 785 F.3d at 511-12. CSLI records are, however, wholly unlike business records such as “credit card statements, bank statements, hotel bills, purchase orders, and billing invoices,” which the government “routinely” obtains from third-party businesses by subpoena. Id. at 506. These sorts of business records merely capture voluntary commercial transactions to which the business and its individual client or customer are parties. See Miller, 425 U.S. at 442. CSLI, on the other hand, records transmissions of radio signals in which the cell phone service subscriber may or may not be an active and voluntary participant. We agree with our sister circuits that a service provider’s business interest in maintaining CSLI records is a relevant consideration in determining whether a subscriber can have a legitimate expectation of privacy in this information. But it is not the only consideration. Courts consider not only such “concepts of real or personal property law” in making this determination but also “‘understandings that are recognized and permitted by society.’” Carter, 525 U.S. at 88 (citation omitted). As we have explained, society recognizes an individual’s privacy interest in her movements over an extended time period as well as her movements in private spaces. The fact 49 that a provider captures this information in its account records, without the subscriber’s involvement, does not extinguish the subscriber’s reasonable expectation of privacy. Applying the third-party doctrine in this context would simply permit the government to convert an individual’s cell phone into a tracking device by examining the massive bank of location information retained by her service provider, and to do so without probable cause. See David Gray & Danielle Citron, The Right to Quantitative Privacy, 98 Minn. L. Rev. 62, 140 (2013) (“If the government lacks legal authority to install and monitor a GPS-enabled tracking device, then it can get the same information by securing locational data from OnStar, Lojac, a cellular phone provider, or any number of ‘apps’ that gather and use locational information as part of their services.” (emphasis added)). This is not a case like Hoffa, where a person assumes the risk that an associate or confidante will disclose her communications to law enforcement, see 385 U.S. at 302-03; nor is this a case like Miller, where a person assumes the risk that a bank will disclose her financial transactions to the government, see 425 U.S. at 443. Cell phone users do not actively or knowingly communicate or “trade” their location information to their service providers as part of the consideration for the services provided, to say nothing of the 50 documentation of such information in reproducible formats. That this information winds up in the provider’s hands as a consequence of how cellular networks function does not and should not affect cell phone users’ reasonable expectations of privacy in this information or society’s respect for that expectation. c. Courts have recognized that not all private information entrusted to third-party providers of communications services is subject to warrantless government inspection. As far back as 1877, the Supreme Court recognized Fourth Amendment protection against warrantless inspection of the contents of mail entrusted to the postal service for delivery. Ex parte Jackson, 96 U.S. 727, 733 (1877). In so holding, the Court recognized a distinction between, on one hand, protected matter “intended to be kept free from inspection, such as letters[] and sealed packages[,]” and, on the other hand, unprotected matter “purposefully left in a condition to be examined” as well as the “outward form and weight” of sealed articles. Id. The Court continued to recognize this distinction 90 years later in Katz: “What a person knowingly exposes to the public, even in his own home or office, is not a subject of Fourth Amendment protection. . . . But what he seeks to preserve as private, even in an area accessible to the public, may be 51 constitutionally protected.” 389 U.S. at 351-52 (citations omitted). Katz involved a Fourth Amendment challenge to use of an electronic recording device attached to the outside of a public phone booth that recorded the petitioner’s side of a phone conversation. Id. at 348-49. Applying the principle that the Fourth Amendment protects that which a person “seeks to preserve as private,” id. at 351, the Court held that “[o]ne who occupies [a public phone booth], shuts the door behind him, and pays the toll that permits him to place a call is surely entitled to assume that the words he utters into the mouthpiece will not be broadcast to the world[,]” id. at 352. Although shutting the door to the phone booth proved inadequate to prevent the petitioner’s private words from being overheard, and indeed would have been inadequate to prevent monitoring by the phone company, the petitioner demonstrated an expectation of privacy society would accept as reasonable. See Smith, 442 U.S. at 746-47 (Stewart, J., dissenting); Katz, 389 U.S. at 361 (Harlan, J., concurring). In the current digital age, courts continue to accord Fourth Amendment protection to information entrusted to communications intermediaries but intended to remain private and free from inspection. Courts have, for example, deemed government inspection of the contents of emails a Fourth Amendment search but have declined to do the same for email 52 address information used to transmit emails. Compare United States v. Warshak, 631 F.3d 266, 287-88 (6th Cir. 2010) (holding that email subscribers enjoy a reasonable expectation of privacy in the content of their emails even though such content is accessible to Internet service providers), with United States v. Forrester, 512 F.3d 500, 510 (9th Cir. 2008) (holding that government surveillance of a computer to discover email address information, IP addresses, and amount of data transmitted by email does not constitute a Fourth Amendment search). The dissent argues essentially that, like the forms of address information at issue in Forrester, CSLI is simply information that facilitates the routing of communications rather than protected content, and on this basis distinguishes cases like Warshak. Post at 124. CSLI is of course more than simple routing information; it tracks a cell phone user’s location across specific points in time. 18 And as previously 18The dissent argues that types of information deemed unworthy of Fourth Amendment protection “‘track[]’ some form of activity when aggregated over time.” Post at 125. To be sure, we do not hold that a person may claim Fourth Amendment protection for records of just any type of information that happens to disclose a location, i.e., her location when she deposits an article of mail or engages in a credit card transaction. We do hold that a person may claim protection for her long-term CSLI because this information may track practically all of the movements a person makes over an extended period of time. This feature sets CSLI apart from the various sorts of address and routing information cited in the dissent. 53 noted, cell phone users generally consider their location information no less sensitive than the contents of emails and phone calls. 19 Like a user of web-based email who intends to maintain the privacy of her messages, however, there is nothing the typical cell phone user can do to hide information about her location from her service provider. 20 In the absence of any evidence that Appellants or cell phone users generally intend for their location information to be open to inspection by others, we cannot treat the fact that CSLI is used to route communications and is recorded by intermediaries as dispositive of Appellants’ claim of Fourth Amendment protection for this information. d. Our review of well settled Fourth Amendment jurisprudence teaches us that, even as technology evolves, protections against government intrusion should remain consistent with those privacy expectations society deems reasonable. See, e.g., United States 19 See supra note 4. 20It seems that, here, Appellants took what little action was possible that might have concealed their personal location information from their service provider. Graham’s service was subscribed in his wife’s name, and Jordan used an alias or proxy on his account, although the record does not indicate that these actions were taken specifically to protect Appellants’ privacy interests. 54 v. U.S. Dist. Court for E. Dist. of Mich., S. Div., 407 U.S. 297, 312 (1972) (“There is, understandably, a deep-seated uneasiness and apprehension that [government’s capability for electronic surveillance] will be used to intrude upon cherished privacy of law-abiding citizens.”); Berger v. State of N.Y., 388 U.S. 41, 62 (1967) (“‘[T]he fantastic advances in the field of electronic communication constitute a great danger to the privacy of the individual; . . . indiscriminate use of such devices in law enforcement raises grave constitutional questions under the Fourth and Fifth Amendments . . . .’”) (quoting Lopez, 373 U.S. at 1389 (Warren, C.J., concurring in the result)). That is not to say that societal expectations of privacy cannot change over time, but the advent of new technology alone – even major technological advances – is not a sufficient basis upon which to infer an equally dramatic shift in people’s privacy expectations. 21 21 In Smith, for instance, the Supreme Court rejected the notion that different constitutional rules should apply to different technological means of engaging in the same form of communication, lest “a crazy quilt” be made of the Fourth Amendment. 442 U.S. at 745. Just as a caller could claim no legitimate expectation of privacy in telephone connections made personally by an operator, Smith could claim no privacy expectation in numbers he dialed to connect his calls through the phone company’s automatic switching equipment. Id. at 744. Smith, in this way, reflects the principle that the use of new technology to hide from view what would otherwise be exposed cannot by itself expand Fourth Amendment rights where none would otherwise exist. (Continued) 55 It turns out that the proliferation of cellular networks has left service providers with a continuing stream of increasingly precise information about the locations and movements of network users. Prior to this development, people generally had no cause for concern that their movements could be tracked to this extent. That new technology has happened to generate and permit retention of this information cannot by itself displace our reasonable privacy expectations; nor can it justify inspection of this information by the government in the absence of judicially determined probable cause. Courts and commentators have for years begun to acknowledge the increasing tension, wrought by our technological age, between the third-party doctrine and the primacy Fourth Amendment doctrine grants our society’s expectations of privacy. The natural corollary to this principle is that a technological advance alone cannot constrict Fourth Amendment protection for private matters that would otherwise be hidden or inaccessible. Confronting the question of “what limits there are upon [the] power of technology to shrink the realm of guaranteed privacy” in Kyllo, 533 U.S. at 34, Justice Scalia concluded for the majority that the use of new technology “to explore details of the home that would previously have been unknowable without physical intrusion” constitutes a search, id. at 40. “This assures preservation of that degree of privacy against government that existed when the Fourth Amendment was adopted.” Id. at 34. As one prominent commentator explained, the Fourth Amendment not only “permit[s] access to that which technology hides” but also “protect[s] that which technology exposes.” Orin S. Kerr, The Case for the Third-Party Doctrine, 107 Mich. L. Rev. 561, 580 (2009). 56 In her concurring opinion in Jones, Justice Sotomayor declared the assumption that people lack reasonable privacy expectations in information held by third parties “ill suited to the digital age, in which people reveal a great deal of information about themselves to third parties in the course of carrying out mundane tasks.” Jones, 132 S. Ct. at 957 (Sotomayor, J., concurring). It is concerning that now, during a time and context in which the viability of the third-party doctrine, “the Lochner of search and seizure law,” Orin S. Kerr, The Case for the ThirdParty Doctrine, 107 Mich. L. Rev. 561, 563 (2009) (footnote omitted), has never been in graver doubt, the dissent’s treatment of the doctrine would expand it into a full-on exception to the legitimate-expectation-of-privacy inquiry. Post at 133. Our dissenting colleague reads into Miller and Smith a rule that would preclude virtually any Fourth Amendment challenge against government inspection of third-party records. But just a few years ago, writing for the Court in Bynum, our dissenting colleague rightly declared that the question of whether an individual has a reasonable expectation of privacy in a matter searched is “[t]he ‘touchstone’ of Fourth Amendment analysis[.]” 604 F.3d 164 (citation omitted). Contrary to her current views, the third-party doctrine was not devised to sidestep this question; rather, the doctrine aids the court 57 precisely in deciding whether certain privacy expectations are reasonable by societal standards. See Smith, 442 U.S. at 743-44; Bynum, 604 F.3d at 164; (Quartavious) Davis, 785 F.3d at 527 (Rosenbaum, J., concurring) (“Supreme Court precedent fairly may be read to suggest that the third-party doctrine must be subordinate to expectations of privacy that society has historically recognized as reasonable.”). Smith and Miller do not endorse blind application of the doctrine in cases where information in which there are clearly reasonable privacy expectations is generated and recorded by a third party through an accident of technology. The third-party doctrine is intended to delimit Fourth Amendment protections where privacy claims are not reasonable - not to diminish Fourth Amendment protections where new technology provides new means for acquiring private information. See Orin S. Kerr, An Equilibrium-Adjustment Theory of the Fourth Amendment, 125 Harv. L. Rev. 476, 527 (2011) (“[I]f a new technology permits the government to access information that it previously could not access without a warrant, using techniques not regulated under preexisting rules that predate that technology, the effect will be that the Fourth Amendment matters less and less over time.”).