The areas of the Constitution the Patriot Act violates:
Violates the Fourth Amendment, which says the government cannot conduct a search without obtaining a warrant and showing probable cause to believe that the person has committed or will commit a crime.
Violates the First Amendment's guarantee of free speech by prohibiting the recipients of search orders even where there is no real need for secrecy.
Violates the First Amendment by effectively authorizing the FBI to launch investigations of American citizens in part for exercising their freedom of speech.
Violates the Fourth Amendment by failing to provide notice - even after the fact - to persons whose privacy has been compromised. Notice is also a key element of due process, which is guaranteed by the Fifth Amendment.