Harv.L.Rev.: Note, Digital Duplications and the Fourth Amendment, 129 Harv. L. Rev. 1046 (2016):
The explosive growth of digital data in the twenty-first century has been both a boon and a curse for law enforcement. On one hand this growth has heralded a “golden age of surveillance” owing to the massive amount of information that is available about actual and potential lawbreakers, but on the other hand the government now has that much more data to sort through. To search this ever-expanding “haystack,” the government has adopted various techniques, including algorithmic queries. But in order to apply these queries — to search for the needle — the government must first collect the hay. One technique that law enforcement has adopted is to take “mirror images” of digital data for later off-site review.
A persistent question, though, is how the Fourth Amendment applies to both the initial act of duplicating digital data and the continued retention of that data. It goes without saying that the drafters of the Fourth Amendment did not contemplate its application to the digital era. And Fourth Amendment jurisprudence, accordingly, has long since departed from a strict originalist understanding. Beginning with Katz v. United States, the Supreme Court adapted “[t]he right of the people to be secure … against unreasonable searches and seizures” to cover modern technological developments by finding such a violation when the government surreptitiously recorded a phone conversation in a public phone booth.
Since then, the Court has considered the Fourth Amendment’s application to a variety of new technologies ranging from airplane surveillance to thermal imaging. In Riley v. California, for example, the Supreme Court analyzed the application of the Fourth Amendment to searches of a cell phone seized incident to arrest. Noting that modern cell phones contain vast troves of personal information, far beyond what one historically could keep in one’s pocket, the Court found that the rationale for the search-incident-to-arrest exception to the warrant requirement did not extend to a cell phone’s digital contents.
This Note attempts to address a narrow question in modern Fourth Amendment jurisprudence: should government duplication and retention of electronically stored information be characterized under the Fourth Amendment as a search, as a seizure, as both, or as neither? Although this Note does explore Fourth Amendment “reasonableness” balancing as applied to duplication and retention in Part IV, its primary focus is on the predicate question of whether a search or seizure has even occurred.
Duplication and retention arise in many contexts. But somewhat shockingly, it is not entirely settled that the government conducts either a search or a seizure when it makes a copy of locally stored data, and then retains that data without further reviewing it. As Justice Sotomayor worries, “[t]he Government can store such records and efficiently mine them for information years into the future.”