As noted by multiple civil libertarian groups, the PATRIOT ACT and its associated laws authorize the government to conduct courts in which the interpretation is not made public, and searches may be authorized without presenting the suspect with a warrant.
Is this permissible under the Constitution? Specifically, what precedent is available on the topics of due process and search and seizure that may inform a court's decision should they take a case challenging the act?
Edit: The parts I am most concerned with are sections 213 (Sneak and Peek), 215 (Access to records), and 218 (Reduced Wiretap Requirements). Although I find many other sections questionable, in the interest of keeping the question fully answerable, I am limiting my choices to these three.