The case as the source of the expectation-of-privacy framework
In the two episodes of The Bob Zadek Show devoted to automated license-plate readers, guest Jonathan Hofer dates the controlling case law on surveillance to the Katz decision, which he places in 1968. He tells Bob Zadek that since the late 1960s, case law in the United States on surveillance topics has largely focused on the question of whether a person has an expectation of privacy, and that this framework comes from Katz The Mass Surveillance nobody is talking about (2022).
Hofer describes the inquiry as asking whether the conduct at issue is like something in plain view or in the public square. Roads, he says, are public, and when those considerations are put together a person does not have an expectation of privacy over a license plate. He adds that the Supreme Court has explicitly addressed the topic and explicitly said there is no expectation of privacy for a license plate, and that it is not illegal to photograph a person’s license plate or to set up a camera on the roadway A PSA on ALPRs (2022).
Hofer also draws a line between that settled ground and a different Fourth Amendment territory that begins once data is aggregated. The expectation-of-privacy test, in his telling, resolves the single-plate question but not the question of what happens when many such readings are combined The Mass Surveillance nobody is talking about (2022).
Private collection versus government use
Zadek presses Hofer on whether a private party may collect and sell license-plate data. He poses the hypothetical of two people who are not law enforcement and not deputized, who put up cameras, build an inventory of plate photographs, package it, and offer it on the internet for $19.95. Hofer answers that they should be totally in the clear and that there are no state or federal laws that would prevent them from doing so A PSA on ALPRs (2022).
Zadek frames the distinction in terms of what the right to privacy describes. In his account, the right to privacy describes the relationship between the individual and government, not the relationship simply between private parties. He characterizes the collection and organization of data by a private party as a business activity, and says it is only when government invites itself to the party and wants to take advantage of the data that the right to privacy is implicated The Mass Surveillance nobody is talking about (2022).
Zadek then describes how the data is aggregated: organizations, governmental and perhaps private, take data from one county and then the next, until the state is covered, and the pots of data can be woven together so that a single license plate can be isolated. Hofer agrees with this description A PSA on ALPRs (2022).
The expectation-of-privacy test applied to plates
The application Hofer gives the Katz framework is narrow. Because roads are public and a license plate is exposed to view, the plate falls on the no-expectation side of the line, and photographing it is not illegal. He treats the aggregation problem as a separate Fourth Amendment question rather than as a continuation of the plate question The Mass Surveillance nobody is talking about (2022).
Zadek’s contribution to the exchange is to insist that the private-party case and the government case be kept apart. He asks whether a private party that has acquired the right, by lease or easement, to place cameras and collect data is free to sell that data, and whether any privacy regulation governs the activity. Hofer’s answer is that no such state or federal law exists A PSA on ALPRs (2022).
Across episodes: no development
The topic is touched on in “The Mass Surveillance nobody is talking about” and “A PSA on ALPRs,” both with Jonathan Hofer; the excerpts show the same exchange reproduced in both episodes, with no change in the treatment of Katz between them.
What the sources do not cover
The excerpts do not state the holding of Katz v. United States, which amendment it turned on, or the name of any Justice who wrote in it. They do not identify the Supreme Court decision Hofer refers to when he says the Court has explicitly addressed license plates. They do not give the city or state in which the underlying events occurred, nor the outcome of any prosecution or challenge. The excerpts also break off before Hofer’s personal story about a wrongful stop is told.