Pole camera surveillance of a resident was reasonable and the mosaic theory did not apply. United States v. Green, 2025 U.S. App. LEXIS 20410 (D.C. Cir. Aug. 12, 2025):
Since Jones, the Supreme Court has signaled a continuing willingness to consider the aggregation of data as distinctively problematic. See, e.g., Riley v. California, 573 U.S. 373, 394 (2014) (noting that the “sum of an individual’s private life” can be adduced from a warrantless search of a cellphone). In United States v. Carpenter, the Court concluded that collecting seven days of cell-site location information (CSLI) was a search under the Fourth Amendment (despite precedent suggesting a contrary result). 585 U.S. at 315, 310 n.3.8 The Court endorsed the theory propounded by Justices Sotomayor and Alito and found that “individuals have a reasonable expectation of privacy in the whole of their physical movements,” even if exposed to public view, and that accessing the CSLI data contravened that expectation. Id. at 310-11. It noted that the CSLI data presented “even greater privacy concerns” than the vehicle GPS data in Jones because a cellphone “follows its owner beyond public thoroughfares and into private residences, doctor’s offices, political headquarters, and other potentially revealing locales,” allowing the government to create a comprehensive map of a person’s movements with “just the click of a button.” Id. at 311-12.
At the same time, the Court cautioned that its decision was “a narrow one” and that it did not “call into question conventional surveillance techniques and tools, such as security cameras.” Id. at 316. It also left undisturbed the holding in Knotts, in which case it held that using a more “rudimentary tracking” device that simply “augmented visual surveillance” for discrete intervals was not a search. Id. at 306 (citing United States v. Knotts, 460 U.S. 276, 281-85 (1983)) (citation modified).
Pole cameras pose a special challenge to the mosaic theory. In one sense, they are among the most common forms of surveillance. They rely on a public, unobstructed vantage point and off-the-shelf technology, not unlike an agent with binoculars perched atop a telephone pole. But unlike that unfortunate agent—who will get bored, blink or need to stretch—a pole camera never looks away. It records everything, 24/7, for weeks or months, even years, preserving everything it sees. By aggregating that data, critics worry, the government can reconstruct not only what happens at a location, but also the patterns and relationships of the individuals who pass through it. Little about the underlying camera technology has changed in recent years but Carpenter’s embrace of the mosaic theory has made pole-camera challenges newly relevant to the Fourth Amendment. And as other technologies like artificial intelligence and facial recognition improve, the potential capabilities of ubiquitous cameras may grow exponentially.
Still, other circuit courts have consistently rejected attempts to extend the mosaic theory to pole cameras. See supra n.3. Those decisions primarily rely on the continuing vitality of the public-view doctrine as the Supreme Court has articulated it, including Carpenter’s reassurance that it did not invalidate the use of traditional surveillance techniques like “security cameras.” See, e.g., Tuggle, 4 F.4th at 525-26 (quoting Carpenter, 585 U.S. at 316). They also sometimes note that, even if pole-camera surveillance could violate the Fourth Amendment, the duration of the evidence in their respective cases was not sufficient to establish such a violation. See, e.g., id. (18 months permissible but noting the “obvious line-drawing problem: How much pole camera surveillance is too much?”); Harry, 130 F.4th at 348 (50 days); Hay, 95 F.4th at 1316-17 (68 days); see also Carpenter, 585 U.S. at 322-23 (Kennedy, J., dissenting) (deriding the arbitrariness of the majority’s six-day cutoff).
More fundamentally, there seems a material difference between the types of data the Supreme Court has found to implicate mosaic-type concerns—such as omnipresent location tracking—and the more limited information a fixed pole camera can capture. The cell-site location data in Carpenter, like the GPS data in Jones, “provide[d] an all-encompassing record of the holder’s whereabouts,” revealing “not only his particular movements, but through them his ‘familial, political, professional, religious, and sexual associations.’” Carpenter, 585 U.S. at 311 (quoting Jones, 565 U.S. at 415 (Sotomayor, J., concurring)). Those kinds of data have a “retrospective quality” that allows the government to reconstruct a suspect’s past—surveilling him before he was ever a suspect—and to access “a category of information otherwise unknowable.” Id. at 312.
By contrast, the observational power of a single pole camera is both fixed and limited. The Fourth Amendment “protects people, not places,” Katz, 389 U.S. at 351, so the simple fact that a public-facing camera records a location continuously is not itself constitutionally suspect. The question is what the government in fact learns about an individual from that camera’s limited perspective. The information may still be meaningful—agents might see when a person comes and goes, who visits him or how often he mows the lawn—but it would tell them nothing about him outside the frame. The footage, in other words, “only depict[s] one small part of a much larger whole.” Tuggle, 4 F.4th at 524. There is a difference between location-tracking technologies, which follow a person broadly but shallowly, and fixed surveillance tools, which observe narrowly but in greater depth. As an analogy, if an individual’s daily patterns were the surface of the ocean, CSLI or GPS data would be a buoy drifting across the water, reporting any contacts along the way. But a pole camera is anchored in place—it might provide complete information about the reef it rests on but say little about the sea beyond.
In any event, this case is a poor candidate for applying the mosaic theory to pole-camera surveillance. The footage here spanned only two days—far shorter than the weeks or months involved in other cases where courts have had reservations about cumulative observation. Given that brief duration, the government had no opportunity to compile a retrospective record of Green’s movements or reconstruct his patterns of life. Nor did the footage itself reveal much—the camera captured just two fleeting moments in which Green stepped outside, offering no insight into his associations, routines or private conduct in the manner condemned in Carpenter. Whatever the outer bounds of the mosaic theory may be, they are not approached here. This was short-term, public-facing surveillance, limited in scope. It did not implicate the privacy concerns the mosaic theory is intended to address.
We emphasize, however, the limits of our holding. We do not suggest that pole-camera surveillance could never amount to a Fourth Amendment search. In another case, the technology might be used over longer periods, with more cameras, or in combination with other tools—such as facial recognition, automated tracking or artificial intelligence—to build a far more comprehensive portrait of an individual’s life. Whether such surveillance would raise constitutional concerns, however, is a question left for another day.
In sum, the rear of 917 Wahler was exposed to public view and the surveillance was brief and unsophisticated. Under the public-view doctrine, Green lacked any objectively reasonable expectation of privacy. And because the observation was both limited and discrete, the mosaic theory does not change that result.
