“ We read the papers filed by the United States in these two cases as stating that the surveillances neither invaded the premises of the other petitioners nor overheard their conversation. lance was unlawful.' Of course, a finding by the District Court that the surveillance was lawful would make disclosure and further proceedings unnecessary. Similarly, it is not clear that each petitioner has standing to assert the illegality of the surveillance or of the introduction of its fruits. ”

“ It is not evident from the records in some of these cases whether the surveillances at issue were unlawful. It may be that the overhearings in some instances were not achieved by trespass, see Katz v. United States, 389 U.S. 347, 88 S.Ct. 507, 19 L.Ed.2d 576 (1967) ; Desist v. ”