Final version: 'Executing Warrants for Digital Evidence: The Case for Use Restrictions on Nonresponsive Data'

I have recently posted the final version of a new article on computer warrants, "Executing Warrants for Digital Evidence: The Case for Use Restrictions on Nonresponsive Data," 48 Texas Tech L. Rev. 1 (2015). The article is a reworked version of a keynote address I gave at last year's annual criminal law symposium at Texas Tech. Here's the abstract:

This Article considers how the Fourth Amendment should limit the process of executing search warrants for digital evidence. Warrants for digital evidence are normally executed in two stages. First, agents enter the physical place to be searched and seize all computers. Second, agents conduct an electronic search for the responsive data described in the warrant. The two-stage process raises the prospect that warrants for digital evidence will be executed in ways that resemble general warrants. If agents can seize everything at the first stage, and see all the data at the second stage, what stops agents from accessing and using a target's entire digital world every time a computer warrant is executed?

This Article argues that the Fourth Amendment should be interpreted to impose a use restriction on nonresponsive data seized during the execution of computer warrants. After reviewing the various ways courts could limit the execution of computer warrants, it concludes that use restrictions are the best way to restore the traditional limits on searches for the new technological environment of computers. The Article then revisits the Author's earlier conclusion that courts can achieve that result by eliminating the plain view exception for computer searches. While still a possible approach, eliminating the plain view exception raises underappreciated doctrinal puzzles.

The better path is for courts to rule that the Fourth Amendment imposes use restrictions on nonresponsive data because use transforms the underlying seizure from a justified and modest step needed to execute the warrant to an unjustified and invasive seizure unrelated to the warrant itself. Agents can overseize at the first stage because they must, and they can search through all the data for the responsive files because there is no other way to ensure that they find all the evidence described in the warrant. But when agents use nonresponsive data, the seizure of that data is no longer justified by the warrant and ordinarily is no longer reasonable. This approach also allows courts to impose an exigent circumstances exception to the use restriction: When a review of nonresponsive files reveals exigent circumstances, agents can use the nonresponsive files to address the exigency.