Potter Stewart

“ The Fourth Amendment provides that 'no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.' The purpose of these clear and precise words was to guarantee to the people of this Nation that they should forever be secure from the general searches and unrestrained seizures that had been a hated hallmark of colonial rule under the notorious writs of assistance of the British Crown. ”

“ There can be no doubt, therefore, that the agents were lawfully present in the appellant's house, lawfully authorized to search for any and all of the items specified in the warrant, and lawfully empowered to seize and such items they might find. [4] It follows, therefore, that the agents were acting within the authority of the warrant when they proceeded to the appellant's upstairs bedroom and pulled open the drawers of his desk. But when they found in one of those drawers not gambling material but moving picture films, the warrant gave them no authority to seize the films. ”

“ This is not a case where agents in the course of a lawful search came upon contraband, criminal activity, or criminal evidence [5] in plain view. For the record makes clear that the contents of the films could not be determined by mere inspection. And this is not a case that presents any questions as to the permissible scope of a search made incident to a lawful arrest. For the appellant had not been arrested when the agents found the films. After finding them, the agents spent some 50 minutes exhibiting them by means of the appellant's projector in another upstairs room. ”