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There are many instances in which warrantless surveillance has been held to be permissible under the Fourth Amendment. Searches in public schools require neither warrants nor a showing of probable cause. Government offices can be searched for evidence of work-related misconduct without warrants. So can searches conducted at the border, or searches undertaken as a condition of parole. Searches have been upheld in the absence of a warrant where there is no legitimate expectation of privacy. The Clinton administration conducted a warrantless search — lawfully — when it was trying to determine what the spy Aldrich Ames was up to. The day after Pearl Harbor, President Roosevelt authorized the interception of all communications traffic into and out of the United States.