USMJ concludes the Fifth Circuit’s geofence warrant case means a cell tower dump warrant is unreasonable. In re Four Applications for Search Warrants Seeking Info. Associated with Particular Cellular Towers, 2025 U.S. Dist. LEXIS 32995 (S.D. Miss. Feb. 21, 2025):
Before the Court are four search-warrant applications for location-and-time based cell-tower data, also known as tower-dump or tower-extraction warrants. The applications seek to obtain from four separate cellular service providers a list of phone numbers and identifiers for cellular devices that connected to cell towers covering nine locations during specific windows of time ranging from ten minutes to one hour for each location. The applications also request information about all communications made using those towers during the specified times. The time windows and locations correspond to crimes the Government suspects were committed by members of a violent street gang. Based on the Fifth Circuit’s recent decision in United States v. Smith, 110 F.4th 817, 820 (5th Cir. 2024), in which the court concluded that geofence warrants are per se “unconstitutional under the Fourth Amendment,” the Court concludes these tower-dump search warrants cannot be issued consistent with the Fourth Amendment. For the reasons explained below, the Court therefore declines to issue the warrants.
. . .
B. The requested warrants fail to satisfy the Fourth Amendment.
Having concluded that a tower dump is a search, the Court turns to whether the Government’s warrant applications are “supported by probable cause and particularity.” Smith, 110 F.4th at 836; see U.S. Const. amend. IV (“[N]o warrants shall issue, but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.”). The Fourth Amendment was adopted in “response to the reviled ‘general warrants’ and ‘writs of assistance’ of the colonial era, which allowed British officers to rummage through homes in an unrestrained search for evidence of criminal activity.” Smith, 110 F.4th at 836 (quoting Riley, 573 U.S. at 403); see id. (“‘General warrants’ are warrants that ‘specif[y] only an offense,’ leaving ‘to the discretion of the executing officials the decision as to which persons should be arrested and which places should be searched.'” (quoting Steagald v. United States, 451 U.S. 204, 220 (1981))). To satisfy the Fourth Amendment, “a search or seizure of a person must be supported by probable cause particularized with respect to that person.” Ybarra v. Illinois, 444 U.S. 85, 91 (1979). Critically, “[t]his requirement cannot be undercut or avoided by simply pointing to the fact that coincidentally there exists probable cause to search or seize another or to search the premises where the person may happen to be.” Id. “[A] person’s mere propinquity to others independently suspected of criminal activity does not, without more, give rise to probable cause to search that person.” Id.
With this framework in mind, the Fifth Circuit in Smith concluded that “[g]eofence warrants present the exact sort of ‘general, exploratory rummaging’ that the Fourth Amendment was designed to prevent.” Smith, 110 F.4th at 837 (quoting Coolidge v. New Hampshire, 403 U.S. 443, 467 (1971)). The court noted that geofence warrants “never include a specific user to be identified, only a temporal and geographic location where any given user may turn up post-search” and concluded “[t]hat is constitutionally insufficient.” Id. The court quoted favorably from a law review article that supported its conclusion that geofence warrants do not satisfy the Fourth Amendment:
As professor Stephen Henderson explains in his discussion of CSLI, focusing probable cause on the group rather than the individual “would mean that a larger database is always preferred” by law enforcement, because “by definition there will be evidence of crime in that larger set.” Stephen E. Henderson, Response, A Rose by Any Other Name: Regulating Law Enforcement Bulk Metadata Collection, 94 Tex. L. Rev. See Also 28, 40-41 (2016). Doing so leads to an “absurd” understanding of probable cause: “[A] prosecutor confident that a bank customer is committing tax fraud could access the combined records of all customers of that bank because, somewhere in there, she is very sure is evidence of crime.” Id. at 41. Henderson argues, in the context of CSLI, it must be the case that probable cause is required for “each person’s obtained records,” meaning here “each phone number contained within the dump.” Id.
Smith, 110 F.4th at 837 n.11.
For the reasons the Fifth Circuit articulated in Smith, the Court concludes that the Government’s tower-dump warrant applications are not supported by probable cause and particularity. For starters, while the Government has some idea of who may have been involved in one or more of the crimes—the affidavits supporting the warrant applications list seven potential suspects—the Government has not presented probable cause to believe that any particular individual committed any of the specific crimes described. The warrant applications also arguably present probable cause to believe that the searches will reveal the location data of some unknown perpetrators of the crimes. See Mem. at 3 (explaining that affidavits describe “the belief that the cell towers will contain evidence of [who committed] the offenses”). But this is not enough. If the Court were to issue the warrants, it would be authorizing the Government to search the data for every cellular device (including cell phones) of every single individual near the crime scenes without a showing of probable cause as to each individual. See Ybarra, 444 U.S. at 92 n.4 (“[A] warrant to search a place cannot normally be construed to authorize a search of each individual in that place.”).
Stated another way, the Government is essentially asking the Court to allow it access to an entire haystack because it may contain a needle. But the Government lacks probable cause both as to the needle’s identifying characteristics and as to the many other flakes of hay in the stack. And unlike in Smith, where only three devices turned up in the geofence in rural DeSoto County, Mississippi, the haystack here could involve the location data of thousands of cell phone users in various urban and suburban areas. As in Smith, the tower-dump warrant applications “present the exact sort of ‘general, exploratory rummaging’ that the Fourth Amendment was designed to prevent.” Smith, 110 F.4th at 837 (quoting Coolidge, 403 U.S. at 467). And because they are “general warrants,” they are “categorically prohibited by the Fourth Amendment.” Id. at 838.
Update: techdirt: Magistrate Judge: If Geofence Warrants Are Unconstitutional, So Are Cell Tower Dumps by Tim Cushing
