I doubt one is able to amass a fortune of over a billion dollars, without first learning how to exploit the U.S. Internal Revenue Code.

Even more importantly, when a federal circuit court opines on the constitutionality of a federal statute, it will result in mass filings of "identical" lawsuits in other circuits by similarly situated plaintiffs (especially when the ACLU is involved). Since the constitution grants us an appeal of right to the federal circuit court of appeals in these matters, these other circuits will become bombarded with requests to reach a decision and have little choice but to rule.
Lastly, and most significantly, if another circuit reaches a contrary decision, SCOTUS will have little choice but to grant certiorari -- it would be impractical to expect the FBI to abide by different rules amongst different circuits when dealing with Patriot Act matters.

Last summer I interned for a federal district judge; guess who was bound by his rulings in the majority of cases?
The parties, that's it!