CA7: City’s use of “smart meter” is a search, but it is reasonable because it’s not for criminal purposes and law enforcement never knows

The use of a smart meter to collect energy consumption in homes is a search under the Fourth Amendment under Kyllo. It is, however, a reasonable search because it is purely for the use of the power company and city in monitoring overall consumption and not a part of a criminal investigation. The court notes that if the intervals were shorter or the information was being collected for criminal investigation, the outcome might well be different. Also, the third party doctrine provides no refuge for the city because there is no third party. Naperville Smart Meter Awareness v. City of Naperville, 2018 U.S. App. LEXIS 22834 (7th Cir. Aug. 16, 2018):

The technology-assisted data collection that Smart Meter Awareness alleges here is at least as rich as that found to be a search in Kyllo. Indeed, the group alleges that energy-consumption data collected at fifteen-minute intervals reveals when people are home, when people are away, when people sleep and eat, what types of appliances are in the home, and when those appliances are used. (R. 102-1 at 14.) By contrast, Kyllo merely revealed that something in the home was emitting a large amount of energy (in the form of heat).

It’s true that observers of smart-meter data must make some inferences to conclude, for instance, that an occupant is showering, or eating, or sleeping. But Kyllo rejected the “extraordinary assertion that anything learned through ‘an inference’ cannot be a search.” Id. at 36 (quoting id. at 44 (Stevens, J., dissenting)). What’s more, the data collected by Naperville can be used to draw the exact inference that troubled the Court in Kyllo. There, law enforcement “concluded that [a home’s occupant] was using halide lights to grow marijuana in his house” based on an excessive amount of energy coming from the home. Id. at 30. Here too, law enforcement could conclude that an occupant was using grow lights from incredibly high meter readings, particularly if the power was drawn at odd hours. In fact, the data collected by Naperville could prove even more intrusive. By analyzing the energy consumption of a home over time in concert with appliance load profiles for grow lights, Naperville law enforcement could “conclude” that a resident was using the lights with more confidence than those using thermal imaging could ever hope for. With little effort, they could conduct this analysis for many homes over many years.

Under Kyllo, however, even an extremely invasive technology can evade the warrant requirement if it is “in general public use.” Id. at 40. While more and more energy providers are encouraging (or in this case forcing) their customers to permit the installation of smart meters, the meters are not yet so pervasive that they fall into this class. To be sure, the exact contours of this qualifier are unclear—since Kyllo, the Supreme Court has offered little guidance. But Kyllo itself suggests that the use of technology is not a search when the technology is both widely available and routinely used by the general public. See id. at 39 n.6 (quoting California v. Ciraolo, 476 U.S. 207, 215 (1986) (“In an age where private and commercial flight in the public airways is routine, it is unreasonable for respondent to expect that his marijuana plants were constitutionally protected from being observed with the naked eye from an altitude of 1,000 feet.”)). Smart meters, by contrast, have been adopted only by a portion of a highly specialized industry.

The ever-accelerating pace of technological development carries serious privacy implications. Smart meters are no exception. Their data, even when collected at fifteen-minute intervals, reveals details about the home that would be otherwise unavailable to government officials with a physical search. Naperville therefore “searches” its residents’ homes when it collects this data.

Before continuing, we address one wrinkle to the search analysis. Naperville argues that the third-party doctrine renders the Fourth Amendment’s protections irrelevant here. Under that doctrine, a person surrenders her expectation of privacy in information by voluntarily sharing it with a third party. See Carpenter v. United States, 138 S. Ct. 2206, 2216 (2018) (citing Smith v. Maryland, 442 U.S. 735, 743-744 (1979) and United States v. Miller, 425 U.S. 435, 443 (1976)). Thus, when a government authority gathers the information from the third party, it does not run afoul of the Fourth Amendment. Id. Referencing this doctrine, Naperville argues that its citizens sacrifice their expectation of privacy in smart-meter data by entering into a “voluntary relationship” to purchase electricity from the city.

This argument is unpersuasive. As a threshold matter, Smart Meter Awareness challenges the collection of the data by Naperville’s public utility. There is no third party involved in the exchange. Moreover, were we to assume that Naperville’s public utility was a third party, the doctrine would still provide Naperville no refuge. The third-party doctrine rests on “the notion that an individual has a reduced expectation of privacy in information knowingly shared with another.” Carpenter, 138 S. Ct. at 2219. But in this context, a choice to share data imposed by fiat is no choice at all. If a person does not—in any meaningful sense—”voluntarily ‘assume the risk’ of turning over a comprehensive dossier of physical movements” by choosing to use a cell phone, Carpenter, 138 S. Ct. at 2220 (quoting Smith, 442 U.S. at 745), it also goes that a home occupant does not assume the risk of near constant monitoring by choosing to have electricity in her home. We therefore doubt that Smith and Miller extend this far.