In the last decade, magistrate judges around the United States have introduced a new practice of regulating the search and seizure of computers by imposing restrictions on computer warrants. These ex ante restrictions are imposed as conditions of obtaining a warrant: Magistrate judges refuse to sign warrant applications unless the government agrees to the magistrate’s limitation on how the warrant will be executed. These limitations vary from magistrate to magistrate, but they generally target four different stages of how computer warrants are executed: the on-site seizure of computers, the timing of the subsequent off-site search, the method of the off-site search, and the return of the seized computers when searches are complete.
This Article contends that ex ante restrictions on the execution of computer warrants are both unconstitutional and unwise. The Fourth Amendment does not permit judges to devise limits on the execution of warrants. When such limits are imposed, they have no legal effect. The imposition of ex ante limits on computer warrants is also harmful: Ex ante assessments of reasonableness in ex parte proceedings are highly error-prone, and they end up prohibiting reasonable practices when paired with ex post review. Although ex ante restrictions may seem necessary in light of the present uncertainty of computer search and seizure law, such restrictions end up having the opposite effect. By transforming litigation of the lawfulness of a warrant’s execution into litigation focusing on compliance with restrictions rather than reasonableness, ex ante restrictions prevent the development of reasonableness standards to be imposed ex post that are needed to regulate the new computer search process. Magistrate judges should refuse to impose such restrictions and should let the law develop via judicial review ex post.