COVID-19, Digital Surveillance, and Privacy: Fourth Amendment Considerations
Legal Sidebari
COVID-19, Digital Surveillance, and Privacy:
Fourth Amendment Considerations
April 16, 2020
As COVID-19 has spread across the globe, countries like South Korea and Israel have employed digital
surveillance measures using cell phone location data, among other things, in an effort to track and limit
the virus’s transmission. In the United States, the federal government and some state and local
governments have reportedly begun to gather geolocation data voluntarily provided by the mobile
advertising industry to assess how people are continuing to move and congregate during the pandemic.
Technology companies such as Google and Facebook have also discussed leveraging some of their
aggregated and anonymized location data for similar purposes. Moreover, the recently passed CARES Act
provides, as part of new funding for the Department of Health and Human Services’ Centers for Disease
Control and Prevention (CDC), that the CDC must report to Congress within 30 days on “the
development of a public health surveillance and data collection system for coronavirus.” In light of these
developments, some commentators have speculated about the potential in the United States for more
invasive, obligatory data collection and tracking practices emulating the measures taken in some other
parts of the world.
Actions by the federal or state governments to surveil U.S. citizens in response to the COVID-19
pandemic could raise a host of legal issues, but as one commentator recently recognized, the Fourth
Amendment to the U.S. Constitution may “determine the outer bounds of permissible surveillance at the
federal and state levels” in this context. This Sidebar accordingly provides an overview of the Fourth
Amendment and certain relevant doctrines and exceptions before discussing how the relevant legal
frameworks could apply to coronavirus-related government surveillance.
Fourth Amendment Overview
The Fourth Amendment to the United States Constitution protects against “unreasonable searches and
seizures” and provides that “no Warrants shall issue, but upon probable cause,” among other things. The
Supreme Court has recognized that the fundamental purpose of the Amendment “is to safeguard the
privacy and security of individuals against arbitrary invasions by governmental officials.” Though often
discussed and applied in the context of law enforcement efforts to obtain evidence of criminal
wrongdoing, and though such efforts often must satisfy stricter requirements than in other contexts, “[i]t
is well settled that the Fourth Amendment’s protection extends beyond the sphere of criminal
Congressional Research Service
https://crsreports.congress.gov
LSB10449
CRS Legal Sidebar
Prepared for Members and
Committees of Congress
Congressional Research Service
2
investigations.” As the text of the constitutional provision suggests, the question of whether official action
has run afoul of the Amendment’s dictates entails consideration of at least two distinct analytical
components: (1) the existence of a search or seizure, and (2) the reasonableness of that search or seizure.
Existence of a Search and the Third-Party Doctrine
A Fourth Amendment “search” can occur either when government agents physically intrude on a
“constitutionally protected area” or, even absent a physical trespass, when officials violate a person’s
“reasonable expectation of privacy.” In simple terms, absent a physical intrusion on a constitutionally
protected area, “[w]hen an individual seeks to preserve something as private, and his expectation of
privacy is one that society is prepared to recognize as reasonable, . . . official intrusion into that private
sphere generally qualifies as a search . . . .”
As an outgrowth of the jurisprudential focus on the “reasonable expectation of privacy,” a line of cases
from the 1970s developed what is known as the “third-party doctrine.” The broad proposition for which
these cases stand is that “a person has no legitimate expectation of privacy in information he voluntarily
turns over to third parties.” Recognition of this principle led the Supreme Court in United States v. Miller
to conclude that the government’s subpoena of a suspect’s bank records did not constitute a Fourth
Amendment search, as the documents contained “only information voluntarily conveyed to the banks and
exposed to their employees in the ordinary course of business.” The Court appeared to take an expansive
view of the third-party doctrine in Miller, expounding that a person “takes the risk, in revealing his affairs
to another, that the information will be conveyed by that person to the Government.” Thus, the Court held
that the Fourth Amendment does not prohibit the government from obtaining information revealed to a
third party even if it is assumed that “the confidence placed in the third party will not be betrayed.”
Following Miller, the Court applied the same principles in the context of information conveyed to a
telephone company in Smith v. Maryland. The Court in Smith ruled that the government’s acquisition of
outgoing phone numbers dialed on a landline telephone was not a search, reasoning that telephone
subscribers know the numbers they dial are used by the telephone company “for a variety of legitimate
business purposes.” As such, when Smith placed a call, he “voluntarily conveyed” the dialed numbers to
the phone company by “expos[ing] that information to its equipment in the ordinary course of business”
and consequently “assumed the risk” that the company’s records would be divulged.
In its 2018 decision in Carpenter v. United States, however, the Court appeared to retreat from a broad
conception of the third-party doctrine, at least as applied to certain kinds of digital information held by
third-party companies. Carpenter involved the compelled disclosure by wireless carriers of customers’
historical “cell-site location information” (CSLI), which is essentially a historical log of a cell phone’s
connections to geographical network access points. Law enforcement can use CSLI to determine a cell
phone’s location over time with a relatively high degree of accuracy. The Carpenter Court held that,
given the “unique nature of cell phone location records,” “the fact that the information is held by a third
party does not by itself overcome the user’s claim to Fourth Amendment protection.” The Court
emphasized that the doctrine requires consideration of “the nature of the particular documents sought.”
On this basis, the Court distinguished prior third-party-doctrine cases as involving “limited types of
personal information,” pointing out that the information and documents at issue in Miller and Smith were
“not confidential communications” or otherwise revealing of highly private affairs. By contrast, the
Carpenter Court viewed it as significant that CSLI “provides an intimate window into a person’s life,
revealing not only his particular movements, but through them his familial, political, professional,
religious, and sexual associations.” The Court also discounted one of the rationales underlying the third-
party doctrine—that information has been voluntarily exposed—in the case of CSLI, writing that such
information “is not truly ‘shared’ as one normally understands the term” because “a cell phone logs a cell-
site record by dint of its operation, without any affirmative act on the part of the user beyond powering
up.” For these reasons, the Supreme Court concluded that the government’s acquisition of customer cell-
Congressional Research Service
3
site records from third-party carriers was a search within the meaning of the Fourth Amendment.
Nevertheless, the Court characterized its ruling as a narrow one, noting that it did “not disturb the
application of Smith or Miller, call into question” other surveillance tools like security cameras, address
“other business records that might incidentally reveal location information,” or consider “collection
techniques involving foreign affairs or national security.”
Reasonableness and Special Needs
Once it is established that a Fourth Amendment search has occurred, the question becomes whether that
search was “reasonable.” Whether a particular class of searches meets the reasonableness standard may
depend on context. Where a search is conducted “by law enforcement officials to discover evidence of
criminal wrongdoing,” and subject to “a few specifically established and well-delineated exceptions,”
reasonableness ordinarily requires that the government first obtain a judicial warrant based on probable
cause before a search can occur. For instance, after concluding that the acquisition of CSLI from third-
party carriers in Carpenter was a Fourth Amendment search, the Court applied the general rule and held
that “police must get a warrant when collecting CSLI to assist in the mine-run criminal investigation[.]”
That said, neither a warrant nor probable cause is “required to establish the reasonableness of all
government searches.” Among other things, the warrant and probable cause requirements may be
inapplicable “when special needs, beyond the normal need for law enforcement,” make those
requirements “impracticable.” Such special needs may include, for example, the need to maintain order in
the public school context or “the operational realities of the [public] workplace.” In cases where the Court
has applied the so-called “special needs” doctrine, it has generally balanced the individual and
governmental interests at issue, focusing on a variety of factors. These factors have included the scope of
the privacy interest at stake, the degree of intrusion on that interest, the immediacy and significance of the
governmental concern, and the efficacy of the intrusion in meeting the concern. Though the circumstances
in which this “special needs” doctrine may apply defy easy categorization, when the factors tip the
balance in favor of the government, searches or seizures without a warrant and even without any
individualized suspicion of wrongdoing—like sobriety checkpoints or random drug testing in some
situations—may be considered reasonable and thus comport with the Fourth Amendment. The Supreme
Court has specifically noted in this regard that a “risk to public safety [that] is substantial and real” may
justify “blanket suspicionless searches calibrated to the risk,” citing as examples the routine searches
conducted at airports and entrances to some official buildings.
One apparent strand of the “special needs” doctrine is a category of cases in which courts have upheld
searches conducted pursuant to legislative or administrative regulatory regimes—such as those that may
apply to probationers or in certain industries—without the need for a warrant supported by probable
cause. At least in circumstances that are sufficiently distinct from ordinary law enforcement, courts have
sometimes employed a balancing test similar to the one described above where “reasonable legislative or
administrative standards” are in place to preclude arbitrariness.
Application to Potential COVID-19-Related Surveillance
Assuming the federal or a state government is involved in efforts to surveil or track the movements of
U.S. citizens in response to the COVID-19 pandemic, the first question for purposes of constitutional
analysis would be whether such efforts amount to a Fourth Amendment search, which could depend on
the means, source, and scope of the information sought or obtained. The use of traditional surveillance
devices such as security cameras to monitor compliance with stay-at-home orders, for instance, might not
implicate constitutional concerns if limited to public locations for a brief period of time, as such devices
may not “present the kind of aggregate view of intimate details of” a person’s movements that concerned
the Court in Carpenter. Additionally, monitoring through mobile apps or other means, such as opt-in
Congressional Research Service
4
Bluetooth contact tracing that does not rely on location data, could be seen by a court as unobjectionable
if voluntary in nature and limited in scope. However, a government effort to acquire information more
akin to the circumstances of Carpenter—i.e., compelled provision of location data on specific individuals
from companies in possession of the information—might present a closer question. Though third-party
doctrine precedent prior to Carpenter would suggest that exposure of information to third-party
companies could negate any reasonable expectation of privacy in that information, the Court in Carpenter
made clear that it intends to view its precedent and the doctrine flexibly in the face of “seismic shifts in
digital technology” that give third parties access to vast swaths of information revealing “the privacies of
life.”
Assuming the existence of a Fourth Amendment search, the constitutionality of government surveillance
or data collection efforts would depend upon the reasonableness of the search. This inquiry is fact-bound
and ultimately dependent on the context in which the search takes place. Efforts to obtain at least some
kinds of location information as evidence of criminal wrongdoing for purposes of ordinary law
enforcement could require a warrant based on probable cause unless an exception existed (e.g., if exigent
circumstances, such as preventing imminent harm, negated the need for a warrant).
Beyond the context of ordinary law enforcement, it might be argued that containment of a deadly virus
constitutes a special need that could justify some form of warrantless, suspicionless surveillance or data
collection. There is some authority to support the proposition that preventing the spread of a
communicable disease could be considered a special need under the Fourth Amendment in certain
circumstances. A court faced with such an argument would likely balance the individual and
governmental interests at issue as described above, which would involve fact-specific consideration of the
scope of the intrusion (e.g., anonymized contact tracing or acquisition of limited kinds of personal
information versus broader surveillance or acquisition of precise location data over time) as well as the
government’s concern. In this latter regard, given the Supreme Court’s recognition that a substantial “risk
to public safety” may justify calibrated suspicionless searches, a court could view the balance as tipping
in favor of government surveillance while the COVID-19 pandemic is ongoing. That said, because of how
fact-dependent the special needs analysis is, it is difficult to say with certainty how a court would rule.
Even cases involving the same type of privacy interest and incursion—such as drug testing—have
produced disparate results depending on the other factors a court may consider.
Given the highly fact-specific and fluid nature of the relevant constitutional doctrines, as well as the
privacy and governmental interests at stake, Congress may consider whether to act. Congress might
attempt to establish standards for governmental acquisition of digital-location or other kinds of
information in response to the COVID-19 pandemic, which could factor into a court’s analysis of
reasonableness. That said, Congress may not legislate away constitutional protections, and thus any
legislative framework authorizing suspicionless searches would need to be sufficiently “calibrated” to the
ostensible special needs of disease detection and spread prevention. Existing federal and state laws may
also regulate the government’s ability to obtain and use certain kinds of personal information related to
the pandemic. Congress could impose further statutory limits if it perceives the protections of the Fourth
Amendment or existing laws to be lacking in this context, as it has done with respect to the contents of
electronic communications held by certain kinds of third-party companies, though there would remain the
possibility that statutory limits could be superseded by an intervening judicial decision interpreting the
Constitution.
Congressional Research Service
5
Author Information
Michael A. Foster
Legislative Attorney
Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff
to congressional committees and Members of Congress. It operates solely at the behest of and under the direction of
Congress. Information in a CRS Report should not be relied upon for purposes other than public understanding of
information that has been provided by CRS to Members of Congress in connection with CRS’s institutional role.
CRS Reports, as a work of the United States Government, are not subject to copyright protection in the United
States. Any CRS Report may be reproduced and distributed in its entirety without permission from CRS. However,
as a CRS Report may include copyrighted images or material from a third party, you may need to obtain the
permission of the copyright holder if you wish to copy or otherwise use copyrighted material.
LSB10449 · VERSION 1 · NEW