INCLUDED ARE HISTORIES OF THE DEPARTMENT OF JUSTICE'S POSITION AND PRACTICE WITH RESPECT TO THE USE OF BOTH TELEPHONE WIRETAPPING AND TRESPASSORY PLACEMENT OF MICROPHONES, AND THE INTERPRETATION OF THE FOURTH AMENDMENT BY THE SUPREME COURT. LEVI MAINTAINS THAT ELECTRONIC SURVEILLANCE CONDUCTED FOR FOREIGN INTELLIGENCE PURPOSES, ESSENTIAL TO THE NATIONAL SECURITY, IS LAWFUL UNDER THE FOURTH AMENDMENT, EVEN IN THE ABSENCE OF A WARRANT, AT LEAST WHERE THE SUBJECT OF THE SUREVILLANCE IS A FOREIGN POWER OR AN AGENT OR COLLABORATOR OF A FOREIGN POWER.