Academic journal article
By Kerr, Orin S.
Harvard Law Review , Vol. 119, No. 2
How does the Fourth Amendment apply to the search and seizure of computer data? The Fourth Amendment was created to regulate entering homes and seizing physical evidence, but its prohibition of unreasonable searches and seizures is now being called on to regulate a very different process: retrieval of digital evidence from electronic storage devices. Although obvious analogies exist between searching physical spaces and searching computers, important differences between them will force courts to rethink the key concepts of the Fourth Amendment. What does it mean to "search" computer data? When is computer data "seized"? When is a computer search or seizure "reasonable"?
This Article offers a normative framework for applying the Fourth Amendment to searches of computer hard drives and other storage devices. It begins by exploring the basic differences between physical searches of tangible property and electronic searches of digital evidence. It then considers how the Fourth Amendment should apply when a government investigator retrieves evidence from a person's computer, and concludes that exposing data to an output device such as a monitor should be a Fourth Amendment "search" ordinarily requiring a warrant. Although copying data should not be deemed a "seizure" of that data, imaging a computer should be regulated by the Fourth Amendment and searches of copies should be treated the same as searches of the original. In the final section, the Article considers ways to limit the scope of computer searches. The plain view exception may need to be narrowed or even eliminated in digital evidence cases to ensure that digital warrants that are narrow in theory do not devolve into general warrants in practice. Tailoring the doctrine to the realities of computer investigations will protect the function of existing Fourth Amendment rules in the new environment of digital evidence.
In the last decade, personal computers have become an increasingly important source of evidence in criminal cases. Computers record and store a remarkable amount of information about what users write, see, hear, and do. In a growing number of cases, searching the suspect's personal computer is an essential step in the investigation. The thorny issue for the courts--and the fascinating issue for scholars--is how the Fourth Amendment should regulate the process. How does the Fourth Amendment govern the steps that an investigator takes when retrieving evidence from a personal computer? At present, the answer is surprisingly unclear. (1) Lower courts have just begun to grapple with the question, resulting in a series of tentative and often contradictory opinions that leaves many answers unresolved. (2)
The problem is difficult because important differences exist between the mechanisms of physical and digital evidence collection. The Fourth Amendment was drafted to regulate searches of homes and physical property, and the courts have developed clear rules to regulate the enter-and-retrieve mechanism of traditional physical searches. (3) Computer searches offer a very different dynamic: electric heads pass over billions of magnetized spots on metal disks, transforming those spots into data that is processed and directed to users via monitors. How can the old rules fit the new facts? For example, what does it mean to "search" computer data? When is computer data "seized"? When is a search or seizure of computer data "reasonable"? These questions are particularly difficult because computers challenge several of the basic assumptions underlying Fourth Amendment doctrine. Computers are like containers in a physical sense, homes in a virtual sense, and vast warehouses in an informational sense. Which insights should govern?
This Article develops a normative framework for applying the Fourth Amendment to searches of computer hard drives and other electronic storage devices. (4) It explores the various ways that the Fourth Amendment could apply to the retrieval of evidence from computers and charts out a recommended path. …