by William G. Walant*
The Fourth Amendment’s “reasonableness clause” provides that citizens have a right “to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures[.]”1 Courts generally ask two questions in determining if a Fourth Amendment violation has occurred: (1) whether the alleged government conduct constitutes a “search” within the meaning of the Fourth Amendment, and (2) whether the search was “reasonable.”2
As to the first question, a search implicates the Fourth Amendment if it frustrates an individual’s “reasonable expectation of privacy”3 or if it constitutes a trespass done “for the purpose of obtaining information.”4,5 But this constitutional protection against unreasonable searches does not apply to a non-government party’s search.6 If such private party does commence a search and presents the findings to the police, the police are under no obligation to “avert their eyes.”7 It is with these principles in mind that the “private search doctrine” was born: a government intrusion subsequent to a private party’s intrusion is not a search under the meaning of the Fourth Amendment if the government has “virtual certainty” that the search will expose no more than what the private party’s earlier intrusion had revealed.8
The Supreme Court has not addressed how the private search doctrine applies to a present-day electronic media storage device (“EMSD”), such as a smart phone or a flash drive. Indeed, the Court has not ruled directly on the doctrine since the 1980s.9 However, in Riley v. California,10 the Court made clear that smart phones implicate substantial privacy interests.11 As a result, the Court sub silentio made a per se rule: regardless of whether a private search precedes a government search, an officer must obtain a warrant to search a smart phone.12 Still, the water is murkier for devices that are not as obviously pervasive in our lives or personally revealing as smart phones. Specifically, EMSDs such as flash drives, ZIP drives, and floppy disks are perfect use-cases to explore the outer-bounds of Riley and the private search doctrine because they are more limited in physical size and memory storage than mobile phones, they are generally unconnected to the internet, and they usually require that a party actually move or copy files onto the device.
Without clear guidance from the Supreme Court, the circuits that have ruled on this issue are split. The Fifth and Seventh Circuits have adopted a “broad” approach by analogizing EMSDs to closed containers: if a private party opens the EMSD (read: “closed container”) and if the officers are substantially certain as to the rest of the contents in the EMSD, then the officers can view those contents regardless of whether or not the private party has already viewed them.13 For example, in United States v. Runyan,14 private parties had collected floppy disks, CDs, and ZIP disks of the defendant. They only partially examined some of the floppies and CDs, where they saw child pornography, but did not view any of the ZIPs.15 Police officers were handed these disks and viewed all of them in their entirety.16 While the Fifth Circuit found that viewing the previously completely unexamined ZIPs, floppies, and CDs did exceed the private search doctrine, it also held that the officers did not exceed the doctrine when they viewed all of the files on the previously partially examined floppies and CDs, which it called “closed containers,” because they were substantially certain as to their contents.17 In short, “the police do not exceed the private search when they examine more items within a closed container than did the private searchers.”18
Similarly, in Rann v. Atchison,19 a private party brought the defendant’s camera memory card and computer zip drive that had child pornography to the police. Because the parties brought this evidence to support allegations of child pornography, the Seventh Circuit found it reasonable to conclude that the officers knew the devices contained child pornography.20 As to the officers’ subsequent search, relying on Runyan,21 the court said that even if the police more thoroughly searched the digital media devices than [the private parties], . . . the police search did not exceed or expand the scope of the initial private searches. Because [the private parties] knew the contents of the digital media devices when they delivered them to the police, the police were “substantially certain” the devices contained child pornography.22
Other courts, such as the Sixth and Eleventh Circuits and the United States Court of Appeals for the Armed Forces, have instead adopted a “narrower” approach than the Fifth and Seventh Circuits.23 As more fully illustrated below, these courts recognize the special issues that technology raises in the Fourth Amendment context, so, depending on the device at-hand, “the scope of the private search can be measured by what the private actor actually viewed as opposed to what the private actor had access to view.”24
For instance, in United States v. Lichtenberger,25 a private party hacked into the defendant’s laptop and clicked on different folders, where she saw images of sex acts with minors. When the police arrived, she randomly clicked on a few of the images, about four or five, but told the officer she had viewed about one hundred.26 Although the case involved a laptop, rather than the type of EMSD directly addressed by this Contribution, the Sixth Circuit court reasoned that the private search doctrine was violated by broadly asserting that “searches of physical spaces and the items they contain differ in significant ways from searches of complex electronic devices under the Fourth Amendment. . . . The reality of modern data storage is that the possibilities are expansive.”27
Indeed, three years after Lichtenberger, the Sixth Circuit was presented with a case involving the type of EMSDs addressed in this Contribution in United States v. Chapman-Sexton.28 There, the police recovered a stolen flash drive and PlayStation of the defendant, and, upon learning from a third-party that the devices contained child pornography, looked at three images on the flash drive.29 While the majority did not directly address the private search doctrine because it opted to instead rule based on the “inevitable discovery” doctrine,30 Judge John Bush noted in his concurring opinion that “[o]ne could argue that Lichtenberger’s reasoning extends (though it did not explicitly say so) to all electronic devices” and so he could “not say that the private-search doctrine is necessarily satisfied here based on our circuit’s precedent.”31
Similarly, in the Eleventh Circuit case United States v. Sparks,32 an officer received a cell phone from private parties who had clicked on some of its stored images. One of the private parties scrolled through the entirety of the album for the officer and showed just one of the videos, but the officer subsequently viewed another video on the phone.33 The Eleventh Circuit concluded that the officer’s subsequent, more thorough examination of the images they were shown did not violate the private search doctrine.34 However, since the private party had not viewed all of the videos, nor shown all of them to the officer, the officer’s later warrantless inspection of the other video violated the private search doctrine and thus constituted a search.35
The Sixth and Eleventh Circuit’s narrow approach better comports with the logical and legal underpinnings of the private search doctrine. In the context of an EMSD, the private search doctrine requires that a government actor stay within the confines of what the private parties actually viewed. Although officers may legally exceed those confines if they are so certain as to the contents of the item that their search would only provide confirmation of what the private party had relayed to them, in the context of EMSDs, those situations are few and far between—and cannot come about by mere partial exposure of some of an EMSD’s contents. As explained more fully below, the Sixth and Eleventh Circuits recognize these limitations and thus have the better of the two approaches.
First, the private search doctrine is grounded in the “plain view doctrine,”36 so, contrary to what the Fifth and Seventh Circuits suggest, a partial invasion by a private party generally cannot justify an officer’s subsequent full invasion. Under the plain view doctrine, a person has no reasonable expectation of privacy over that which is exposed to the public; if it has not been exposed, then any reasonable expectation of privacy that exists is preserved.37 Accordingly, in terms of the private search doctrine, if a private search “merely frustrate[s] that expectation in part,” then a “partial invasion cannot automatically justify a total invasion.”38 This reasoning must be the case—for the doctrine to mean anything otherwise would create an arbitrary double standard, whereby a warrant requires particularity, but a warrantless search is limitless as long as it is in some way initiated by a private person.39
Officers can exceed what has already been exposed or viewed,40 but only under very specific circumstances,41 which leads to the second point: those circumstances are much more limited than the Fifth and Seventh Circuits acknowledge. When the government is able to exceed what was literally viewed during a prior private search, it may do so only if “there was virtual certainty that [further inspection] . . . would not tell [the officer] anything more than he had already been told.”42 This “virtual” or “substantial” certainty requirement is meant to be extremely narrow. For instance, in Jacobsen, even though FedEx employees had only seen white powder in a bag after they opened a box, the officers went further by analyzing the white powder. Yet, the Court found that because the drug test could only verify whether the powder was cocaine, “the likelihood that official conduct of the kind disclosed by the record will actually compromise any legitimate interest in privacy seems much too remote to characterize the testing a search subject to the Fourth Amendment.”43 In reaching this determination, the Court cited United States v. Place,44 wherein the use of a canine to sniff for narcotics in luggage at an airport was found to not be a search in part because “[i]t d[id] not expose noncontraband items that otherwise would remain hidden from public view.”45
The Sixth and Eleventh Circuits’ narrow approach to EMSDs best comports with those two underlying principles. First, as recognized by these Circuits, EMSDs have the potential to hold vastly more information than traditional physical containers, thereby raising the probability that an officer will intrude upon previously unviewed private information.46 An average floppy disk can hold 1.44 megabytes of storage47 and a typical CD can hold 700 megabytes; comparatively, some of the smallest flash drives on the market hold 64,000 megabytes and some of the largest reach 1,000,0000 megabytes.48 It is thus intellectually disingenuous to simply analogize EMSDs to “containers,” as the Fifth and Seventh Circuits have done—EMSDs are more like containers with nesting dolls of other containers that each, in turn, hold nesting dolls of still more containers. Indeed, a hard drive itself has been described as “simultaneously [a] file cabinet (with millions of files) and [a] locked desk drawer; [it] can be repositories of innocent and deeply personal information.”49 The likelihood that a legitimate privacy interest will be compromised during the examination of an EMSD’s contents is, borrowing from the words of Jacobsen, not so “remote” as to avoid being characterized a search under the Fourth Amendment.50
Moreover, the narrow approach recognizes the heightened privacy interests inhered in the content of EMSDs. EMSDs—and the devices they connect to, such as computers—have grown substantially more personal as they have become pervasive staples in our lives.51 This nuance further raises the prospect that the information an officer will intrude upon will be among an individual’s most sensitive.52 It therefore cannot (and should not) be the case that the government stays within the confines of the private search doctrine if an officer can examine the entirety of an EMSD merely on the grounds that a private party partially viewed its contents and the officer searched “more thoroughly” than the private party.53 Further, the pervasiveness of EMSDs means that they will hold a more wide and varied collection of personal information than most traditional, physical items, which lessens the chance that an officer can draw more than an inference as to their contents based on a private party’s mere partial viewing.54
The narrow approach advocated by this Contribution is not without its faults. As explained in more detail below, first, EMSDs arguably do not pose the same privacy concerns as computers or smart phones, especially given that EMSDs are usually not connected to the internet and their contents are often filtered by a private party. Second, the narrow approach seems to create an extremely fact-specific criterion that will be too onerous for courts to apply, arguably suggesting that we should just abandon the private search doctrine as we know it and fully prohibit, with some exceptions, warrantless government searches of EMSDs. Third, and in the same vein, the narrow approach might undercut expeditious investigations or result in arbitrary line-drawing tasks for courts. This Contribution will now address each of these objections, in turn. As discussed more fully below, these concerns are at worst, non-fatal, and at best, illusory.
It is true that EMSDs do not pose exactly the same privacy concerns as computers or smart phones. For instance, unlike the smart phone in Riley, EMSDs are usually not connected to the internet. However, this difference only matters in degree, not in kind. First, Riley was a consolidation of two cases, one of which involved an older model cell phone that did not have the same internet connectivity features as the newer smart phone55—a distinguishment nary mentioned by the Court. Second, the Court repeatedly emphasized that electronic devices like computers increase the privacy interests at stake because of their storage capacity—separate and apart from whether they are connected to the internet.56 As noted above, EMSDs like flash drives clearly raise storage capacity issues both in the amount of information they can hold and in the amount of personal and unrelated files they will likely contain, albeit not necessarily to the same extent as computers or smart phones.57
It is also true that EMSDs generally require copying files from a source, such as a computer. As a result, the contents of an EMSD are arguably filtered or curated by a private party and, in turn, the expectation of privacy in those contents are frustrated or diminished by the time an officer receives the EMSD.58 Indeed, the Court has on numerous occasions declined to constrain an officer’s ability to conduct a warrantless search of a container when an expectation of privacy in that container has already been frustrated or diminished.59 However, per Jacobsen, what matters in the context of the private search doctrine is the reasonableness of the officer’s search at the time that the officer made the intrusion, which can depend upon what information the private party had relayed to the officer.60 Regardless of the fact that a private party has copied files onto the drive, if they have made no assurance that an EMSD only contains files they have actually viewed, an officer cannot be sufficiently certain that a subsequent search will avoid untouched privacy interests because of the unique nature of EMSDs.61
As explained more fully below, the scenario where a private party, uninfluenced and uncoerced, makes a representation such that an officer has sufficient certainty to satisfy the private search doctrine for an EMSD is very limited.62 Some recent scholarship has thus argued that the Supreme Court should simply “exempt” EMSDs from the private search doctrine altogether—that is, the Court would categorically deem EMSDs unsearchable absent a warrant or other exception, so the doctrine would never apply to EMSDs.63 However, creating such an exemption is unnecessary. EMSDs can fit nicely into the private search doctrine and create a socially desirable outcome because the narrow approach effectively creates a per se rule: absent an unusual circumstance, “it [would be] virtually impossible for law enforcement to be sufficiently certain of what they will find upon the digital device.”64 As a result, in almost every case, the officer will not be able to examine the EMSD within the confines of the private search doctrine and thus will be required to obtain a warrant.
In fact, the narrow approach to the private search doctrine actually encourages officers to seek warrants or, at the very least, perform basic investigative due diligence65 when reviewing an EMSD handed over by a private party—even if a private party represents that they have viewed every file in the EMSD. A reasonable officer, ceteris paribus, would likely prefer to guarantee admittance of evidence ex ante, as opposed to risk suppression and fight for admittance ex post.66 An officer could gamble and not perform any investigative diligence of a private party’s representation, but given the nature of EMSDs and the narrow approach, there is a high chance that the officer will come upon new information and a court will suppress such evidence. If the officer performs due diligence and does not come upon new content, then the private search doctrine has worked as it should; however, ex ante, there is still a high risk that the officer will come upon new content during the due diligence that will later be suppressed. Taking stock of all these steps, this lack of certainty67 would likely encourage officers to seek a warrant.
Encouraging warrants is, of course, a socially desirable outcome. A central purpose of the Fourth Amendment is to protect privacy,68 which is most effectively achieved when government searches are mediated by a neutral magistrate.69 “Over and again this Court has emphasized that the mandate of the (Fourth) Amendment requires adherence to judicial processes, and that searches conducted . . . without [a warrant] are per se unreasonable under the Fourth Amendment—subject only to a few specifically established and well-delineated exceptions.”70
Still, the narrow approach as applied to digital information might impose stringent and unrealistic guidelines on government agents.71 Effectively requiring an officer to sit down with a private party to review each and every file or to obtain a warrant could slow down investigations that need to be swiftly completed. However, the Supreme Court has never sacrificed the warrant requirement simply because an investigation might be slowed.72 Warrants can also now be obtained more easily than ever, such as via the phone,73 and the Court has declined to ignore the warrant requirement when warrants can be easily obtained.74 Further, the narrow approach does not purport to get rid of other exceptions to the warrant requirement, such as exigency. The critical point is instead that the government action will constitute a search and require further justification in order for it to be conducted without a warrant.
Since the narrow approach focuses on the nature of the device, it poses another distinct problem: courts will have to draw lines as to which devices constitute EMSDs, in addition to evaluating an officer’s level of “certainty” based on the information that was relayed by the private party and determining what privacy interests were already frustrated by the private party. Yet, this task is not as worrying as it seems at first blush. The Court has noted that the Fourth Amendment generally requires a fact-specific inquiry in the first place.75 Moreover, the key question is not what constitutes an EMSD, but whether the officers had substantial certainty as to the contents of the device before performing their investigation, which can be informed by the type of device that holds the contents. If a reasonable officer would know that the device in its ordinary usage has the potential to store thousands of files, and if the private party has not made a contrary representation, then the narrow approach should apply.76
Courts must be careful “not to uncritically extend existing precedents” when confronted with new concerns brought by technology.77 Extending the private search doctrine over EMSDs beyond the confines of the narrow approach would give an officer the ability to freely scour potentially thousands of untouched, private files. The Court should not allow that to be the law. Indeed, the Fourth Amendment was enacted in response to general warrants and writs of assistance, as famously argued against by James Otis in 1761, whereby government officials could rummage through a private party’s possessions without the check of a detached magistrate.78 The narrow approach to the private search doctrine both remains faithful to the Fourth Amendment and encourages officers to seek warrants—two outcomes that are undoubtedly beneficial for all of society.
* William G. Walant is a J.D. Candidate (2022) at New York University School of Law. This Contribution is a commentary on a problem presented in the Prince Evidence Moot Court Competition held in March 2021. The views expressed in this contribution do not necessarily represent the views of the author. Rather, this Contribution is a distillation of one side of an argument made by the author at the Competition.
1. U.S. Const. amend. IV, cl. 1.
2.Taylor v. City of Saginaw, 922 F.3d 328, 332 (6th Cir. 2019).
3. Katz v. United States, 389 U.S. 347, 360 (1967) (Harlan, J., concurring).
4. United States v. Jones, 565 U.S. 400, 404 (2012).
5. Whether the private search doctrine is limited to the Katz half of the definition of a “search” or extends to the Jones definition is beyond the scope of this Contribution. See generally Andrew MacKie-Mason, The Private Search Doctrine After Jones, 126 Yale L.J. Forum 326 (2017).
6. Burdeau v. McDowell, 256 U.S. 465, 475 (1921).
7. Coolidge v. New Hampshire, 403 U.S. 443, 489 (1971) (plurality opinion).
8. United States v. Jacobsen, 466 U.S. 109, 119 (1984). See also id. at 117 (“The Fourth Amendment is implicated only if the authorities use information with respect to which the expectation of privacy has not already been frustrated.”).
9. See generally id. at 109 (ruling directly on the private search doctrine); Walter v. United States, 447 U.S. 649, 649 (1980) (plurality opinion) (same).
10. 573 U.S. 373 (2014).
11. Id. at 386 (noting, inter alia, that “[a] search of the information on a cell phone bears little resemblance to the type of brief physical search considered in [United States v. Robinson, 414 U.S. 218 (1973)].”).
12. See id. at 401.
13. See Alexandra Gioseffi, Lichtenberger, Sparks, and Wicks: The Future of the Private Search Doctrine, 66 Emory L.J. 395, 424 (2017) (describing the approach adopted by the Fifth and Seventh Circuits as giving “government officials . . . broad authority to search devices more thoroughly and view more files without fear of violating the owners’ Fourth Amendment rights”).
14. 275 F.3d 449 (5th Cir. 2001).
15. Id. at 453.
16. Id. at 453–54.
17. Id. at 463 (“The guideline that emerges . . . is that the police exceed the scope of a prior private search when they examine a closed container that was not opened by the private searchers unless the police are already substantially certain of what is inside that container based on the statements of the private searchers, their replication of the private search, and their expertise.”).
18. Id. at 464.
19. 689 F.3d 832 (7th Cir. 2012).
20. Id. at 838.
21. Specifically, in adopting the Fifth Circuit’s ruling, the Seventh Circuit highlighted the Fifth Circuit’s analogy between digital media storage devices and containers. Id. at 836–37.
22. Id. at 838 (emphasis added).
23. See Gioseffi, supra note 13, at 418.
24. United States v. Wicks, 73 M.J. 93, 100 (C.A.A.F. 2014) (emphasis added). The court in Wicks went on to deduce that, even assuming Runyan was correct in analogizing computer disks to storage containers, cell phones and laptops present unique challenges that demand a different private search doctrine analysis. Id. at 102. See also Orin S. Kerr, Searches and Seizures in A Digital World, 119 Harv. L. Rev. 531, 548 (2005) (“Under this approach, a search of data stored on a hard drive occurs when that data, or information about that data, is exposed to human observation. . . . Under this approach, . . . in the case of a search by a private actor, government agents may view only the information viewed by the private actor unless they first obtain a warrant.”); Gioseffi, supra note 13, at 415 (“The particularity approach developed independently in different jurisdictions, but the common thread among applications remains the agreement that government searches of electronic devices should be narrowly-tailored.”).
25. 786 F.3d 478 (6th Cir. 2015).
26. Id. at 480–81.
27. Id. at 487, 489. Moreover, although Wicks only involved a cell phone and explicitly stated that cell phones and laptops present challenges “well beyond computer disks,” it was only assuming arguendo that computer disks were akin to containers. 73 M.J. at 102.
28. 758 F. App’x 437 (6th Cir. 2018).
29. Id. at 439.
30. Id. at 442.
31. Id. at 453 (Bush, J., concurring in the judgment and concurring in part). Ultimately, Judge Bush found that because “reasonable courts have disagreed—and reasonable officers could be uncertain—about whether the best reading of Jacobsen requires an ex ante or an ex post analysis, or some combination of both,” the officer was acting “objectively reasonable.” Id.
32. 806 F.3d 1323 (11th Cir. 2015), overruled on other grounds by United States v. Ross, 963 F.3d 1056 (11th Cir. 2020) (en banc).
33. Id. at 1331–32.
34. Id. at 1336.
35. Id. (noting that there is no “safe harbor for a governmental search of materials beyond the scope of a private search”).
36. See United States v. Jacobsen, 466 U.S. 109, 130 (1984) (White, J., concurring) (“The private search doctrine thus has much in common with the plain-view doctrine, which is ‘grounded in the proposition that once police are lawfully in a position to observe an item first-hand, its owner’s private interest in that item is lost.’” (quoting Illinois v. Andreas, 463 U.S. 765, 771 (1983))).
37. See Thomas K. Clancy, The Fourth Amendment Aspects of Computer Searches and Seizures: A Perspective and A Primer, 75 Miss. L.J. 193, 243 (2005) (“Underlying the private search doctrine is the view that the private party has already discovered what is in the container; in [Walter]’s words, the private party has eliminated the owner’s reasonable expectation of privacy in the contents of the container.”).
38. Walter v. United States, 447 U.S. 649, 659, 659 n.13 (1980) (plurality opinion).
39. See U.S. Const. amend. IV, cl. 2 (“No warrants shall issue, but upon probable cause . . . particularly describing the place to be searched, and the persons or things to be seized.”); Walter, 447 U.S. at 657 (“If a properly authorized official search is limited by the particular terms of its authorization, at least the same kind of strict limitation must be applied to any official use of a private party’s invasion of another person’s privacy.”).
40. See Jacobsen, 466 U.S. at 115 (the government’s subsequent search “must be tested by the degree to which they exceeded the scope of the private search”).
41. That is, as explained in this paragraph, the “virtual” or “substantial” certainty requirement. See infra note 42 and accompanying text.
42. Jacobsen, 466 U.S. at 119. Indeed, “the critical measures of whether a governmental search exceeds the scope of the private search that preceded it are how much information the government stands to gain when it re-examines the evidence and, relatedly, how certain it is regarding what it will find.” United States v. Lichtenberger, 786 F.3d 478, 485–86 (6th Cir. 2015).
43. Jacobsen, 466 U.S. at 123–24 (emphasis added).
44. 462 U.S. 696 (1983).
45. Id. at 707. See also Walter v. United States, 447 U.S. 649, 657 (1980) (plurality opinion) (finding it insufficient that “[p]rior to the Government screening one could only draw inferences about what was on the films.”).
46. This focus on the nature and contents of EMSDs comports with Riley. In Riley, the Supreme Court emphasized that smart phones present heightened privacy concerns under the Fourth Amendment in large part because of their storage capacity and prevalence in daily life. See Riley v. California, 573 U.S. 373, 394 (2014). While it is true that “an electronic device does not change the fundamentals of [the Fourth Amendment] inquiry . . . under Riley, the nature of the electronic device greatly increases the potential privacy interests at stake, adding weight to one side of the scale while the other remains the same.” Lichtenberger, 786 F.3d at 488.
47. Each “byte” is a measure of storage space, with each megabyte equaling one million bytes of information. For instance, a typical JPEG image is around 5 megabytes. Patrick Whitener, Flash Drive Sizes: How to Find the Correct Size for Your Needs, USB Memory Direct: Blog (July 6, 2021), https://www.usbmemorydirect.com/blog/flash-drive-sizes/.
48. See Floppy Disk Capacity, Digit. Scrapbooking Storage, https://www.digital-scrapbooking-storage.com/floppy-disk-capacity.html (last visited Jan. 20, 2022); CD DVD Storage Media for Preserving Your Digital Memories, Digit. Scrapbooking Storage, https://www.digital-scrapbooking-storage.com/cd-dvd-storage-media.html (last visited Jan. 20, 2022); Whitener, supra note 47.
49. United States v. Comprehensive Drug Testing, Inc., 513 F.3d 1085, 1108 (9th Cir. 2008) (quotation marks omitted), reh’g en banc, 579 F.3d 989 (2009), opinion revised and superseded on other grounds, 621 F.3d 1162 (2010); see also United States v. Crist, 627 F. Supp. 2d 575, 585 (M.D. Penn. 2008) (“Computers are composed of many compartments, among them a ‘hard drive,’ which in turn is composed of many ‘platters,’ or disks.”).
50. United States v. Jacobsen, 466 U.S. 109, 123–24 (1984).
51. Cf. Riley, 573 U.S. at 395 (discussing the pervasiveness of cell phones).
52. For example, the EMSD will likely contain folders with personal messages or intimate photos.
53. United States v. Runyan, 275 F.3d 449, 464 (5th Cir. 2001).
54. See Walter v. United States, 447 U.S. 649, 657 (1980) (plurality opinion). For example, the EMSD will likely contain many unrelated folders, or it may contain photo albums documenting disparate years in someone’s life.
55. See 573 U.S. at 380–81.
56. Id. at 393 (“[M]any [modern cell phones] are in fact minicomputers . . . . One of the most notable distinguishing features of modern cell phones is their immense storage capacity.”) (emphasis added).
57. See supra notes 48, 52, and 54 and accompanying text.
58. For example, a concerned private party downloads the contents of the defendant’s computer onto a flash drive. See, e.g., United States v. Lichtenberger, 786 F.3d 478, 490 n.6 (6th Cir. 2015).
59. See, e.g., United States v. Robinson, 414 U.S. 218, 224 (1973) (holding that the search of a cigarette pack subsequent to an arrest—which already frustrates an expectation of privacy—comports with the Fourth Amendment); California v. Carney, 471 U.S. 386, 391–92 (1985) (holding that mobile homes are subject to the “automobile exception” because they have diminished reasonable expectations of privacy).
60. Under the narrow approach, the scope of the frustrated privacy interests depends on what the private party had actually viewed. Still, the reasonableness of the officer’s search can be assessed by considering what the private party had relayed to the officer. “The reasonableness of an official invasion of the citizen’s privacy must be appraised on the basis of the facts as they existed at the time that invasion occurred.” United States v. Jacobsen, 466 U.S. 109, 115 (1984).
 Further, if an officer instructs or coerces the private party to go through each file, that investigation would likely be considered a search under the Fourth Amendment: the private party is acting under the direction of the officer, deeming them a government agent. See Walter v. United States, 447 U.S. 649, 662 (1980) (Blackmun, J., dissenting) (“[T]he Fourth Amendment proscribes only governmental action, and does not apply to a search or seizure, even an unreasonable one, effected by a private individual not acting as an agent of the Government or with the participation or knowledge of any governmental official.”). The contours of what constitutes “acting as an agent” of the government is beyond the scope of this Contribution.
62. Put succinctly, even if a private party represents they have viewed every file contained in an EMSD, an officer will still be risking suppression given that an EMSD has a large storage capacity and a high chance of holding previously unviewed personal or unrelated files. See supra notes 48, 52, and 54 and accompanying text.
63. See Dylan Bonfigli, Get A Warrant: A Bright-Line Rule for Digital Searches Under the Private-Search Doctrine, 90 S. Cal. L. Rev. 307, 329–30 (2017) (“Instead of trying to fit digital searches into the existing private-search framework, . . . courts should adopt a rule like the one seen in Riley—a bright-line rule that exempts digital searches from the private-search exception.”).
64. Brianna M. Espeland, Implications of the Private Search Doctrine in A Digital Age: Advocating for Limitations on Warrantless Searches Through Adoption of the Virtual File Approach, 53 Idaho L. Rev. 777, 833 (2017).
65. Such due diligence might include walking through the EMSD’s contents with the private party to ensure the party’s representation was accurate.
66. In addition to assuming the officer is reasonable and that a reasonable officer would prefer guaranteed admittance of evidence to the risk of suppression, this calculation assumes that the new information an officer comes upon would be entered in at trial and thus face suppression. An officer may instead decide to improperly intrude upon a privacy interest and never risk suppression because they do not intend to enter that evidence in at trial. Yet, this limitation to suppression’s efficacy as a deterrence mechanism to warrantless searches is inherent in the Supreme Court’s Fourth Amendment doctrine and so is essentially constant; therefore, it should not detract from the conclusion that the narrow approach at least provides a higher incentive to obtain a warrant relative to the broad approach.
67. An officer’s “lack of certainty” as to the contents of an EMSD should not be confused with an officer’s “lack of clarity” as to what constitutes permissible conduct. The Supreme Court has previously noted in a different context that if an officer can never be sure if what they are doing is constitutional, the framework is impermissible. Kyllo v. United States, 533 U.S. 27, 39 (2001). But it is not the case that the narrow approach would mean officers are never clear if what they are doing is constitutional: whether an officer believes they have sufficient certainty to examine the contents of an EMSD will be readily apparent (e.g., the private party represented they viewed all of a flash drive’s files and walked the officer through all of those files but no new content emerged). Rather, the narrow approach means that officers understand they will almost never have sufficient certainty regarding the contents of an EMSD so as to make their conduct constitutional.
68. Camara v. Mun. Court of City and Cty. of S.F., 387 U.S. 523, 528 (1967) (“The basic purpose of this Amendment, as recognized in countless decisions of [the Supreme] Court, is to safeguard the privacy and security of individuals against arbitrary invasions by governmental officials.”).
69. See Johnson v. United States, 333 U.S. 10, 17 (1948) (noting that absolving the warrant requirement “would obliterate one of the most fundamental distinctions between our form of government, where officers are under the law, and the police-state where they are the law.”).
70. Katz v. United States, 389 U.S. 347, 357 (1967) (Harlan, J., concurring) (internal quotations and citations omitted) (first alteration in original).
71. See United States v. Runyan, 275 F.3d 449, 463 (5th Cir. 2001) (calling its broader approach “sensible because it preserves the competing objectives underlying the Fourth Amendment’s protections against warrantless police searches,” which includes balancing the government’s interests); see also Rann v. Atchison, 689 F.3d 832, 837 (7th Cir. 2012) (same).
72. See Mincey v. Arizona, 437 U.S. 385, 393 (1978) (“[T]he mere fact that law enforcement may be made more efficient can never by itself justify disregard of the Fourth Amendment. . . . The investigation of crime would always be simplified if warrants were unnecessary. But the Fourth Amendment reflects the view of those who wrote the Bill of Rights that the privacy of a person’s home and property may not be totally sacrificed in the name of maximum simplicity in enforcement of the criminal law.”).
73. Fed. R. Crim. P. 4.1(d)(3).
74. Cf. Missouri v. McNeely, 569 U.S. 141, 155 (2013) (“[T]echnological developments that enable police officers to secure warrants more quickly, and do so without undermining the neutral magistrate judge’s essential role as a check on police discretion, are relevant to an assessment of exigency.”).
75. See, e.g., Graham v. Connor, 490 U.S. 386, 396 (1989) (“Because ‘[t]he test of reasonableness under the Fourth Amendment is not capable of precise definition or mechanical application,’ . . . its proper application requires careful attention to the facts and circumstances of each particular case.” (quoting Bell v. Wolfish, 441 U.S. 520, 559 (1979))).
76. See United States v. Jacobsen, 466 U.S. 109, 115 (1984). While this Contribution has set out to argue that all EMSDs should be subject to the narrow approach, the approach should at the very least apply to flash drives, given the sheer amount of data they can hold. The Fifth and Seventh Circuits’ holdings regarding CDs, zip drives, and floppy disks, which have comparatively less storage capacities, are then arguably consistent with this approach and might not need to be overturned. See supra note 48.
77. Carpenter v. United States, 138 S. Ct. 2206, 2222 (2018).
78. See Riley v. California, 573 U.S. 373, 403 (2014) (quoting Letter from John Adams to William Tudor (March 29, 1817), in 10 Works of John Adams 247–48 (Boston, Little Brown & Co. 1856)); see also Boyd v. United States, 116 U.S. 616, 625 (1886).