Linsey K. Hogg, KLJ Staff Editor
On Monday, January 9, 2017, the Supreme Court denied certiorari in United States v. Caraballo. In Caraballo, the Second Circuit Court of Appeals joined the discussion on whether a “search” occurs under the Fourth Amendment when law enforcement acquires a defendant’s location information generated by his cell phone from third-party phone service providers. The court did not answer this question directly, but included the “degree of privacy invasion involved” as a factor in concluding that exigent circumstances existed and, thus, justified the “pinging” of the defendant’s cell phone to determine his real-time location. The Second Circuit took a novel approach to this question by diverging from the historical practice of viewing the question of whether a person has a reasonable expectation of privacy as a binary question and instead focusing on the degree of the intrusion on the defendant’s reasonable expectation of privacy.
Cell phones generate two types of location information. One type is historical information, which consists of location data gathered based on the cell towers to which a person’s phone sent signals. This information is called cell-site location information (“CSLI”). The second type of location information is called “pinging.” “Pinging” enables cell phone providers to locate an individual in real-time by “pinging” a person’s phone to collect information regarding the proximity of the phone to cell towers. In other words, a phone service provider sends a command to the phone and the “GPS location of the phone is determined by triangulating the cell phone’s position by reference to three or more network satellites.” The first type of information, CSLI, provides law enforcement with a historical log of where a person has been, and the second type of information, based on “pinging,” provides law enforcement with the current location of a person.
The gathering of these types of location data presents the issue of whether law enforcement conducts a search under the Fourth Amendment obtaining this information. The answer to this issue depends on whether the defendant has a reasonable expectation of privacy that has been violated. In making this determination, courts use the reasonable expectation of privacy test articulated in Katz v. United States.
The Supreme Court has yet to decide whether either of these types of cell phone information, CSLI or “pinging,” constitutes a search under the reasonable expectation of privacy test. In the Courts of Appeals, the Circuits disagree on whether collecting CSLI constitutes a search. A majority of four circuits has concluded that it is not a search based on the third-party doctrine. In comparison, the Third Circuit has concluded CSLI can constitute a violation of reasonable expectation of privacy, and as such, a court has discretion to require a warrant prior to ordering cell service providers to provide a customer’s CSLI, even if an order is obtained under the Stored Communications Act.
With respect to the second type of location information, i.e. “pinging” a defendant’s cell phone to ascertain the real-time location of the phone, only one circuit has ruled. The Sixth Circuit concluded that pinging does not constitute a search under the Fourth Amendment because individuals have no reasonable expectation of privacy in the real-time GPS location of his/her cell phone. Thus, the circuit courts of appeals disagree on CSLI and only one circuit has definitively ruled on “pinging.” Consequently, the Second Circuit found that the law on CSLI is divided, and the law on “pinging” is undecided.
The Second Circuit’s decision not to suppress “pinging” information was interesting in many ways. First, the court did not decide the case based on the assertion that law enforcement acted with a good faith, reasonable belief and, therefore, that suppression was not a proper remedy. This would have allowed the court to dodge the Fourth Amendment issue entirely. Instead, the court resolved the substantive Fourth Amendment question. Second, the court treated CSLI and pinging the same. Third, the court did not analyze the question of the defendant’s reasonable expectation of privacy as a binary, yes-or-no, question. This decision is novel. Instead, the court focused on “the degree” of intrusion by law enforcement on the defendant’s reasonable expectation of privacy.
The court focused on three factors in defining the degree of intrusion on the defendant’s reasonable expectation of privacy as “relatively slight.” The court first took into consideration the officer’s conduct, noting that the officers “showed due regard for the applicable law in conducting their search” by holding a good faith, reasonable belief that federal law authorized warrantless cell phone pinging in this case because the threat of bodily harm was serious and imminent.
The Second Circuit then took into consideration the fact that the defendant’s expectation was “dubious at best.” The court first noted that the search took place before the Supreme Court decided United States v. Jones, and that existing Supreme Court precedent from United States v. Knotts indicated that the defendant had no reasonable expectation of privacy in his location as revealed by electronic devices. The Second Circuit then explicitly stated that the present circuit split among the courts that have spoken to the issue “reinforce[d] the conclusion that the intrusion here was not an established, core privacy value.” Thus, the Second Circuit concluded that the degree of intrusion into the defendant’s privacy was “relatively slight.”
The third factor the Second Circuit took into consideration was that the “pinging” itself was “strictly circumscribed.” Law enforcement used “pinging” over a short period of time, less than two hours, and ceased “pinging” the defendant’s phone as soon as officers confirmed the identity of the defendant. Additionally, “[a]lthough . . . pinging can provide data ‘that reflects a wealth of detail about [a defendant’s] familial, political, professional, religious, and sexual associations,’ the officers did not attempt to elicit such facts . . . .” Law enforcement’s use of information, the court stated, “was no more expansive than necessary to address the exigency” that the officers perceived existed.
This approach of focusing on the degree of intrusion by law enforcement and the degree of the defendant’s expectation of privacy and then subsequently incorporating that conclusion into the overall Fourth Amendment exigency determination is novel. Courts have historically resolved the reasonable expectation of privacy question as a binary, yes-or-no, question. Noticeably, the Second Circuit twice introduces its discussion of the degree to which the officers’ intrusion violates a defendant’s reasonable expectation of privacy with the term “significantly” lest readers miss the shift in approach.
The Second Circuit’s final conclusion is that exigent circumstances justified the warrantless “pinging” of the cell phone due to a multitude of reasons to believe that the defendant was dangerous. This threat, the court reasoned, justified the “pinging” of the defendant’s cell phone because it was a limited intrusion, plausibly consistent with existing law, which the police used in the most limited way possible.
The Second Circuit seems to be indicating a present interest not only in addressing the unanswered question of exactly when does law enforcement’s acquisition of location information—presumably either historical CSLI or real-time GPS tracking— violate the Fourth Amendment, but it seems that the court has also demonstrated a novel approach to making these determinations. The question for the future is how broadly this approach to analyzing the reasonable expectation of privacy will be recognized and accepted. In the Second Circuit, it is now the law in instances involving “pinging” since that was the issue involved in the Caraballo case. Arguably, it is also now the law for collecting historical CSLI because the court seemingly treats CSLI and “pinging” as indistinguishable.
It is feasible that this approach will help courts in determining other controversial technology questions occurring under the Fourth Amendment. Specifically, this approach may be used to resolve comparable questions, such as when law enforcement requests information on a person’s computer use from third-party internet service providers. Furthermore, it may be that this sliding scale approach to analyzing reasonable expectations of privacy could be applied to all cases, not just cases involving technology.
 J.D. expected May, 2018.
 831 F.3d 95 (2d Cir. 2016), cert. denied, 2017 WL 69446.
 See id. at 102 (“[W]e need not today resolve this important and complex Fourth Amendment question.”).
 Id. at 103.
 Id. at 106.
 Id. at 103, 105.
 Id. at 99.
 Katz v. United States, 389 U.S. 347, 361 (1967) (Harlan, J., concurring) (“[T]here is a twofold requirement, first that a person have exhibited an actual (subjective) expectation of privacy and, second, that the expectation be one that society is prepared to recognize as ‘reasonable.’”). The trespass-physical intrusion test arising from United States v. Jones, 132 S. Ct. 945 (2012), and Florida v. Jardines, 133 S. Ct. 1409 (2013), is inapplicable in instances involving cell phone location data because, in those situations, law enforcement does no trespass or physical intrusion.
 Caraballo, 831 F.3d at 106 (noting that “the degree of privacy that adheres to these sorts of information . . . divides those Circuit courts that have spoken to the issue . . . .”).
 United States v. Graham, 824 F.3d 421, 425 (4th Cir. 2016) (en banc) (holding that the government did not violate defendant’s Fourth Amendment rights by obtaining historical cell-site location information from the defendant’s phone service provider without a warrant because defendant had no reasonable expectation of privacy in historical location information); United States v. Carpenter, 819 F.3d 880, 883-84 (6th Cir. 2016) (noting a distinction between the content of a cell phone, to which the Fourth Amendment protects, and the routing information necessary to convey it, which the Fourth Amendment does not protect, and holding that the government did not conduct a search for Fourth Amendment purposes when it acquired cell-site location information because no reasonable expectation of privacy exists); United States v. Davis, 785 F.3d 498, 513 (11th Cir. 2015) (en banc) (holding that defendant has no reasonable expectation to privacy in cell-site location information kept and owned by third-party cell service provider and distinguishing cell-site location information from “real-time tracking of precise movements,” i.e. “pinging”); In re Application of U.S. for Historical Cell Site Data, 724 F.3d 600, 613-14, 615 (adopting a narrow holding that § 2703(d) orders under Stored Communications Act to obtain historical cell-site location “are not categorically unconstitutional” and that, in this case, defendant had no subjective expectation of privacy because cell user had knowledge that his cell phone must necessarily send a signal to nearby cell towers in order to connect his call, that the signal only occurs when the user makes or receives a call, and that the cell user has knowledge that, when this occurs, he/she is transmitting signals to his/her service provider).
 The third-party doctrine provides that a person has no reasonable expectation of privacy in information and that government activity does not constitute a Fourth Amendment search when the government collects data that a person has voluntarily conveyed to a third party. Smith v. Maryland, 442 U.S. 735, 743-45 (1979); United States v. Miller, 425 U.S. 435, 443-44 (1976).
 In re Application of U.S. for an Order Directing a Provider of Elec. Commc’n Serv. to Disclose Records to Gov’t, 620 F.3d 304, 313-317 (3d Cir. 2010).
 United States v. Skinner, 690 F.3d 772, 777 (6th Cir. 2012).
 Caraballo, 831 F.3d at 106.
 Id. at 102 (noting that “an undecided question of whether an underlying privacy interest existed in this case”).
 Id. at 105-06.
 Id. at 102.
 Caraballo, 831 F.3d at 103, 105.
 Id. at 105.
 Id. at 105. In this case, the body of a known affiliate of the defendant had been discovered. The affiliate was found with a fatal gunshot wound to the back of the head and “in a kneeling position with her hands clasped in front of her.” Id. at 97. Additionally, investigating officers knew that undercover officers and confidential informants might interact with the defendant in connection with a drug operation and that the victim had previously disclosed to law enforcement that she feared that the defendant would kill her if he knew she had spoken with cops. Id. at 98.
 Id. at 105.
 132 S. Ct. 945, 949 (2012) (holding that government installation of a GPS device on a defendant’s vehicle and its use to monitor the vehicle’s movements constituted a “search” under the Fourth Amendment).
 460 U.S. 276, 281, 285 (1983) (holding that no search or seizure occurred where government monitored the signal of a beeper placed in a container of chemicals being transported to defendant’s cabin because no legitimate expectation of privacy existed); Caraballo, 831 F.3d at 105-06. There is some ambiguity in reference to the fact that the Jones decision had not yet been handed down. In Jones, the Court explicitly declined to resolve any reasonable expectation of privacy issues. Jones, 132 S. Ct. at 952. Thus, it is unclear as to why the Second Circuit mentions Jones, which focuses only on the trespass-physical invasion test. Id. 949. It is possible that the Second Circuit could be referring to Justice Sotomayor’s concurring opinion indicating that “it may be necessary to reconsider the premise that an individual has no reasonable expectation of privacy in information voluntarily disclosed to third parties.” Id. at 957 (Sotomayor, J., concurring).
 Caraballo, 831 F.3d at 106.
 Id. at 105.
 Id. (quoting United States v. Jones, 132 S. Ct. 945, 955 (2012) (Sotomayor, J., concurring)).
 Id. Cf. Jones, 132 S. Ct. at 948 (discussing the length of time, 28 days, the government used GPS tracking device on the undercarriage of the defendant’s vehicle and that the device relayed more than 2,000 pages of location data over those 28 days).
 Id. at 103 (“Significantly, in making an exigency determination, we have also considered the degree to which the officers, in conducting the search, intruded on a defendant’s privacy interests.”); Id. at 105 (“At the same time, and significantly, the degree of the officer’s intrusion into [the defendant’s] privacy was relatively slight.”).
 Id. at 102. It is also important to point out that the court reorders the questions of the Fourth Amendment analysis.
 Id. at 106.
 See Id. at 102 (listing the different views of the Courts of Appeals without differentiating CLSI and “pinging”); see also United States v. Gilliam, 842 F.3d 801, 804 n.2 (2d Cir. 2016) (explicitly assuming that cell phone users have a reasonable expectation of privacy in location information under the Fourth Amendment).
 For example, even when someone is browsing the internet incognito, he/she is still communicating with his/her third party internet service provider that is still receiving and possibly saving that information. Additionally, if an individual has an android phone and/or has the Google Maps application enabled, that information is being relayed through third party service providers and is saved for an indeterminate amount of time unless the user manually goes in and delete places visited under their “Timeline” on their Google accounts, even if the application is deleted or the phone itself is turned off or replaced. These are only a couple of easily imagined examples where technology users have information shared and stored for indefinite periods of time.
 See, e.g., United States v. Warshak, 631 F.3d 266, 288 (6th Cir. 2010) (holding that defendant had Fourth Amendment right to enjoy reasonable expectation of privacy in his emails vis-à-vis his internet service provider); see generally Florida v. Riley 488 U.S. 445 (1989) (discussing use of technology and reasonable expectations of privacy).
*Featured Image by Jbdodane, licensed under CC BY-NC 2.0.