William O. Douglas,
Zap v. United States — Opinion of the Court
“ A search warrant would be merely the means of insuring the production in court of the primary source of evidence otherwise admissible. Though consent to the inspection did not include consent to the taking of the check, there was no wrongdoing in the method by which the incriminating evidence was obtained. The waiver of such rights to privacy and to immunity as petitioner had respecting this business undertaking for the Government made admissible in evidence all the incriminating facts. We cannot extend the rule of the Weeks case so far as to bar absolutely the check itself. ”
