A cell phone ping is a search under the Fourth Amendment and Washington Constitutions requiring a warrant. It was reasonable here, however, because of exigent circumstances because defendant was a suspect, and the police feared he’d fled. State v. Muhammad, 2019 Wash. LEXIS 732 (Nov. 7, 2019):
¶42 “[E]ven short-term monitoring” can generate a “comprehensive record of a person’s public movements that reflects a wealth of detail about her familial, political, professional, religious, and sexual associations” that can be stored and mined for the future. Jones, 565 U.S. at 415 (Sotomayor, J., concurring). More concerning is the State’s ability to utilize technology’s substantial monitoring and tracking features at low cost, which may “‘alter the relationship between citizen and government in a way that is inimical to democratic society.’” Id. at 416 (quoting United States v. Cuevas-Perez, 640 F.3d 272, 285 (7th Cir. 2011) (Flaum, J., concurring)).
¶43 Courts should take into account the substantial monitoring and tracking capabilities of technology in considering the existence of a reasonable expectation of privacy in public movement. Jones, 565 U.S. at 416 (Sotomayor, J., concurring). In so doing, “[a]ll of these concerns and conclusions about GPS tracking [as set out in Jones] also apply to tracking and monitoring by use of real time cell site location information.” Tracey v. State, 152 So. 3d 504, 519 (Fla. 2014). Accordingly, a cell phone user has a reasonable expectation of privacy in real-time CSLI, and the collection of location data implicates the Fourth Amendment. Id. at 516, 526; see also In re Order Authorizing Disclosure of Location Info., 849 F. Supp. 2d 526, 539 (D. Md. 2011) (finding that a suspect “has a reasonable expectation of privacy … in his location as revealed by real-time location data”).
¶44 Arguments against Carpenter’s application to real-time CSLI focus on the limited nature of the information provided CSLI and the third-party doctrine. Neither argument is persuasive.
¶45 First, the argument that an isolated cell phone ping offers limited information and therefore does not implicate the Fourth Amendment appears to advance what federal courts have deemed the “mosaic” theory. Under this theory, discrete acts of law enforcement surveillance may be lawful in isolation but may otherwise intrude on reasonable expectations of privacy in the aggregate because they “‘paint an “intimate picture” of a defendant’s life.’” Tracey, 152 So. 3d at 520 (quoting United States v. Wilford, 961 F. Supp. 2d 740, 771 (D. Md. 2013)).
¶46 At first glance, the mosaic theory presents an attractive answer to whether a singular cell phone ping constitutes a Fourth Amendment search. But federal courts have recognized the practical problems inherent in this theory when traditional surveillance becomes a search only after some specific period of time elapses. Wilford, 961 F. Supp. 2d at 772 (citing United States v. Graham, 846 F. Supp. 2d 384, 401-03 (D. Md. 2012)). As Graham noted, “discrete acts of law enforcement are either constitutional or they are not.” 846 F. Supp. 2d at 401. For instance, to conclude that one cell phone ping is not a search, provided it lasts less than six hours, yet hold multiple or longer pings do qualify as search is not a workable analysis. See Commonwealth v. Estabrook, 472 Mass. 852, 858, 38 N.E.3d 231 (2015) (concluding no warrant is required to obtain historical CSLI relating to a period of six hours or less). There is no rational point to draw the line; it is arbitrary and unrelated to a reasonable expectation of privacy.
¶47 Rather than offering analysis based on a reasonable expectation of privacy, the mosaic theory instead requires a case-by-case, ad hoc determination of whether the length of time of a cell phone ping violated the Fourth Amendment. It offers little guidance to courts or law enforcement and presents the “danger that constitutional rights will be arbitrarily and inequitably enforced.” Oliver v. United States, 466 U.S. 170, 181-82, 104 S. Ct. 1735, 80 L. Ed. 2d 214 (1984). “‘[I]f police are to have workable rules, the balancing of the competing interests … must in large part be done on a categorical basis—not in an ad hoc, case-by-case fashion by individual police officers.’” Tracey, 152 So. 3d at 521 (alterations in original) (internal quotation marks omitted) (quoting Riley, 573 U.S. at 398).
¶48 Second, the third-party doctrine does not permit a warrantless search of CSLI after the Court’s opinion in Carpenter. Before Carpenter, some federal courts had concluded there was no reasonable expectation of privacy in cell phone location data in possession of third-party service providers. E.g., United States v. Graham, 824 F.3d 421, 427 (4th Cir. 2016). The Carpenter Court explained that the third-party doctrine has failed to keep pace with the “seismic shifts in digital technology.” 138 S. Ct. at 2219. An individual may have a “diminished” privacy interest in location data revealed to third parties, but that alone does not mean “‘the Fourth Amendment falls out of the picture entirely.’” Id. (quoting Riley, 573 U.S. at 392).
¶49 Moreover, voluntary exposure of CSLI “is not truly ‘shared’” as the term is normally understood. Id. at 2220. Cell phones log cell site records “without any affirmative act on the part of the user beyond powering up. Virtually any activity on the phone generates CSLI.” Id. Apart from turning off a cell phone, “there is no way to avoid leaving behind a trail of location data.” Id. Carpenter therefore declined to extend third-party doctrine to the collection of CSLI. Id. Thus, the third-party rationale no longer controls cases concerning historical CSLI data, and its persuasive authority is significantly undercut regarding real-time CSLI data because, as Carpenter stated, individuals maintain an expectation of privacy in the record of their physical movements obtained from CSLI data. 138 S. Ct. at 2217.
¶50 Overall, similar to our discussion of the Washington State Constitution, Fourth Amendment case law indicates that individuals have a subjective expectation of privacy in the location data transmitted by their cell phone. Riley, 573 U.S. at 385 (cell phones are “a pervasive and insistent part of daily life”). This is an expectation that society recognizes as reasonable. See Katz, 389 U.S. at 361 (Harlan, J., concurring). For these reasons, seven members of the court agree that the ping is a search under both article I, section 7 and the Fourth Amendment. See lead opinion of Wiggins, J.; opinion of Gordon McCloud, J.