A key issue will be determining what policy responses to the coronavirus can be squared with the requirements of the Constitution. Many constitutional provisions are implicatedfor example, the Due Process Clause may restrict the government's ability to quarantine people suspected infection, the Commerce Clause (and its judicially crafted inverse, the Dormant Commerce Clause) bears on the question of division of power between the federal government and the states, and the open-ended nature of Article II raises questions about the president's inherent powers to act in the absence of congressional authorization. For now, I want to focus on the Fourth Amendment, which prohibits "unreasonable searches and seizures" and requires that warrants be supported by probable cause, and which will determine the outer bounds of permissible surveillance at the federal and state levels.

A word of warning: Any analysis is going to be highly tentative, for two reasons. First, Fourth Amendment analysis is highly sensitive to factual details about both the surveillance at issue and the broader context (for example, the severity of the pandemic). In the absence of concrete proposals, any analysis is going to necessarily be at a fairly high level. Second, the relevant Fourth Amendment doctrinesthe third-party and special needs doctrinesare, even by the standards of constitutional law, in flux and without much coherence. Any predictions will thus be somewhat speculative.

I'll first give an overview of the relevant Fourth Amendment law and then apply it to three types of disease surveillance that are likely to be relevant in the near term: tracking the occurrence of coronavirus infection, contact tracing and quarantine enforcement.

Much of the legal difficulty, of course, indirectly stems from the text of the Fourth Amendment:

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no 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.

Not all searches and seizures are banned, but just the "unreasonable" ones; and the warrant/probable cause provision doesn't mandate warrants or probable cause, but only requires that a warrant be based on probable cause. That leaves a vast amount open to interpretation (as of course is true for many other constitutional provisions as well), but even more guided than usual by a necessarily vague principle of reasonableness, because "unreasonable" is right there in the text.

Excerpt from:

Disease Surveillance and the Fourth Amendment Reason.com - Reason