The Volokh Conspiracy

Mostly law professors | Sometimes contrarian | Often libertarian | Always independent


Fifth Circuit creates split on whether prospective cell-site collection is a Fourth Amendment 'search'


A month ago, I noted that the Supreme Court was holding some cert petitions on whether the Fourth Amendment protects the collection of historical cell-site records. I argued that there is no split on the question but that there are plausible arguments that the court should take the cases without a split.

On Monday, a closely related split emerged on the collection of prospective cell-site surveillance.

Here's some background. When the government engages in prospective cell-site surveillance, it obtains a court order requiring a cell provider to provide the phone's location at that moment in "real time." That contrasts with collection of historical cell-site records, when the government obtains a court order requiring the provider to hand over stored records retained by a cell provider in the ordinary course of business from some time in the past.

Although every circuit court and state supreme court to rule on historical cell-site collection has concluded it is not a search, the Florida Supreme Court ruled in Tracey v. Florida that prospective cell-site surveillance is a search. As I explained in 2014 when Tracey came down, its precise reasoning is very murky: "The court's opinion lists several concerns and factors," I explained, "none of which seem to be dispositive." This was the key part of the conclusion, however:

For all the foregoing reasons, we conclude that Tracey had a subjective expectation of privacy in the location signals transmitted solely to enable the private and personal use of his cell phone, even on public roads, and that he did not voluntarily convey that information to the service provider for any purpose other than to enable use of his cell phone for its intended purpose. We arrive at this conclusion in part by engaging in the "normative inquiry" envisioned in Smith. See Smith, 442 U.S. at 740 n.5. There, the Supreme Court cautioned that where an individual's subjective expectations have been "conditioned" by influences alien to the well-recognized Fourth Amendment freedoms, a normative inquiry may be necessary to align the individual's expectations with the protections guaranteed in the Fourth Amendment.

Moreover, we conclude that such a subjective expectation of privacy of location as signaled by one's cell phone—even on public roads—is an expectation of privacy that society is now prepared to recognize as objectively reasonable under the Katz "reasonable expectation of privacy" test. See Katz, 389 U.S. at 361 (Harlan, J., concurring) (establishing the two-pronged "reasonable expectation of privacy" test). Therefore, we hold that regardless of Tracey's location on public roads, the use of his cell site location information emanating from his cell phone in order to track him in real time was a search within the purview of the Fourth Amendment for which probable cause was required. Because probable cause did not support the search in this case, and no warrant based on probable cause authorized the use of Tracey's real time cell site location information to track him, the evidence obtained as a result of that search was subject to suppression.

Importantly, Tracey went out of its way to say that it was ruling only on prospective surveillance and not on historical collection. "Nor are historical cell site location records at issue here," Tracey states. And again: "We emphasize, however, that it is not historical cell site location information that is at issue in this case." In my 2014 post on Tracey, I found this limit unpersuasive:

The Florida Supreme Court tried to minimize the split by limiting its opinion to real-time access rather than historical access. But it's hard to imagine how that could make a constitutional difference. That distinction matters in the statutory context because the Stored Communications Act expressly regulates historical access but does not regulate real-time access. But I don't see how it could matter for purposes of the Fourth Amendment question of what is a "search."

Nonetheless, Tracey's formal limit to prospective surveillance was enough to prevent a split.

Until Monday, that is. The U.S. Court of Appeals for the Fifth Circuit ruled in United States v. Wallace that the reasoning of its precedents on historical collection applies equally to prospective cell-site surveillance. In Wallace, the Texas Department of Safety had a warrant out for the arrest of a gang member. The police knew the suspect's cell phone number, so they obtained what the opinion calls a "Ping Order" authorizing the police to determine the locations of cell site towers being
accessed by a number. The opinion later suggests that the ping order was a combination pen/trap order and 2703(d) order obtained under the Texas equivalent of the federal pen register statute and the Stored Communications Act. Put another way, it was not a search warrant based on probable cause. The Fifth Circuit explains that "this information is referred to as 'E911' or prospective cell site data."

A state judge issued the order allowing the surveillance, and the police then "obtained the approximate, real-time GPS location of Wallace's cell phone from AT&T." The location information revealed where William Chance Wallace was located, and the police arrested him based on it and found him in possession of a gun.

Held, per Judge Edith Brown Clement joined by Judges Edith H. Jones and Stephen A. Higginson: The government's act of accessing Wallace's "phone's E911 location information … or prospective cell site data" was not a search. After reviewing its case law holding that collection of historical cell-site records is not a search, the court reasons that there cannot be a Fourth Amendment difference between historical and prospective cell-site surveillance:

There is little distinction between historical and prospective cell site data. As in Historical Cell Site Data, here the government sought "the disclosure of the locations of cell site towers being accessed by cell phone" as recorded in future records "captured, stored, recorded and maintained by the phone companies in the ordinary course of business." "While this information is 'prospective' in the sense that the records had not yet been created at the time the order was authorized, it is no different in substance from the historical cell site information … at the time it is transmitted to the government." Booker, 2013 WL 2903562, at *7. The information the government requested was, "in fact, a stored, historical record because it ed by the cell phone service provider and stored, if only momentarily, before being forwarded to law enforcement officials." In re U.S. for an Order for Prospective Cell Site Location Info. on a Certain Cellular Tel., 460 F. Supp. 2d 448, 459 (S.D.N.Y. 2006). We therefore conclude that like historical cell site information, prospective cell site data falls outside the purview of the Fourth Amendment.

The Fifth Circuit then rules that even if the monitoring was a search, the good-faith exception applies because the government reasonably relied on 18 U.S.C. 2703(c) of the Stored Communications Act:

The plain language of 18 U.S.C. § 2703(c) states that the government may obtain "a court order" requiring a cellular telephone company to turn over "record[s] or other information" related to its "customer[s]." Nothing in the text of the statute suggests that "other information" does not encompass prospective cell site data. Given the "strong presumption of constitutionality due to an Act of Congress," United States v. Watson, 423 U.S. 411, 416 (1976), and the absence of a "clear, controlling case explicitly stating that the government may not obtain real-time cell site location data under the SCA," United States v. Espudo, 954 F. Supp. 2d 1029, 1044 (S.D. Cal. 2013), it was reasonable for the officers to rely on the text of the statute.

Two thoughts.

First, the split between the Fifth Circuit and the Florida Supreme Court seems relatively direct and clear, with one caveat: It's not clear to me that E911 monitoring is the same as prospective cell-site monitoring. If I understand the technology correctly, E911 location information can be implemented either through cell-site triangulation or through obtaining GPS information. I think it depends on the carrier, and perhaps the local network and the phone. The court refers at some points to cell-site surveillance and at other points to GPS surveillance, and it's not entirely clear to me which was at issue in this case. Along the same lines, the Fifth Circuit relies in its opinion on the United States v. Skinner precedent from the Sixth Circuit and describes it as holding "that obtaining prospective cell site data is not a search." As I wrote about here, however, Skinner was a GPS case and not a cell-site case. Because GPS and cell-site surveillance might raise somewhat different issues, I would want to make sure that this was a case of cell-site surveillance and not of GPS surveillance before being confident about the clarity of the split. [Update: I'll probably have a follow-up post on this issue soon.]

Second, the court's alternative holding on the good-faith exception strikes me as problematic. There has been a lot of litigation in the district courts on whether the government can conduct prospective cell-site surveillance with a 2703(d) order. Most of it has concluded, correctly in my view, that 2703(d) cannot apply to prospective surveillance as a matter of statutory law and that a warrant is required by default because no specific surveillance statute applies. The problem is that the Stored Communications Act is about historical collection: Conducting prospective surveillance requires some other authority. Cell-site records are indeed "records or other information" under 2703(c), but you can't interpret that text to allow prospective surveillance given that the statute itself is limited to historical collection. I know I blogged this issue at great length around a decade ago, but I can't quite find the post right now. (I think it was at my short-lived, the archives of which are now only up at the Wayback Machine and aren't easily searchable.) I'll try to dig up my old posts on this if others are interested in the issue.