William J. Brennan, Jr.

“ We think that respondent's assertion misapprehends the thrust of our cases. Of course, if he complies with the subpoena he will not thereafter be able to undo the substantial effort he has exerted in order by comply. [3] But compliance is not the only course open to respondent. If, as he claims, the subpoena is unduly burdensome or otherwise unlawful, he may refuse to comply and litigate those questions in the event that contempt or similar proceedings are brought against him. Should his contentions be rejected at that time by the trial court, they will then be ripe for appellate review. ”

“ But we have consistently held that the necessity for expedition in the administration of the criminal law justifies putting one who seeks to resist the production of desired information to a choice between compliance with a trial court's order to produce prior to any review of that order, and resistance to that order with the concomitant possibility of an adjudication of contempt if his claims are rejected on appeal. ”

“ Read against this background, the District Court's order did nothing more than inform respondent before the event of what efforts the District Court would consider sufficient attempts to comply with the subpoena. We cannot imagine that respondent would be prosecuted for contempt if he produced the documents as required but without attempting to obtain permission from the authorities in Kenya. The additional provisions in the order added nothing to respondent's burden and, if anything, rendered the burden of compliance less onerous. ”