Poorly worded on my part. By "actual" Court, I meant a court whose personnel are appointed pursuant to the appointments clause of the US Constitution.
Sure, they're all created by congress, but the District and Circuit courts have clear, long-established, transparent mechanisms for figuring out who is on the court.
The judicial Power of the United States, shall be vested in one supreme Court, and in such inferior Courts as the Congress may from time to time ordain and establish. The Judges, both of the supreme and inferior Courts, shall hold their Offices during good Behavior, and shall, at stated Times, receive for their Services a Compensation which shall not be diminished during their Continuance in Office.
Congress has an authority to create courts as they see fit, now FISA might not be perfect it might be a complete disaster, but it's not unique as all modern courts have issues on being completely transparent at all times.
For example court orders such as search and seizure, peak and enter, wiretap etc' cant be public for obvious reasons since you can't argue that when you need to tap some one's phone to gather enough evidence to convict them of a crime you can make it public.
You could also argue that such warrants violate the whole "innocent until proven guilty" posture by simply issuing a warrant before there's actual evidence of that a crime has been committed, or in fact it allows the state to force people to incriminate them selves in future crimes.
Now back to the FISA court the hearings and it's orders on specific efforts against specific targets can't be public, some oversight and process transparency might be possible but you can't make a court like that public.
That said the US is pretty much the only country which actually has a court like that, everyone spies, not to the extent that the US does but no one else have those resources, but I haven't heared about any other country in which the intelligence services have not only executive/legislative oversights but also judicial.
I'm not sure how much I trust a judicial oversight that has rejected somewhere in the range of 11 out of 34000 petitions. And it may not even be the FISA court's fault:
“The FISC is forced to rely upon the accuracy of the information that is provided to the court,” Judge Reggie Walton, chief judge of the Foreign Intelligence Surveillance Court (aka FISA court) wrote. “The FISC does not have the capacity to investigate issues of noncompliance, and in that respect the FISC is in the same position as any other court when it comes to enforcing [government] compliance with its orders.”[1]
The utter and complete lack of transparency around the FISA court pretty much makes it impossible to verify that information. We are left with the Executive saying, "Trust us, we won't do anything wrong".
Sure, they're all created by congress, but the District and Circuit courts have clear, long-established, transparent mechanisms for figuring out who is on the court.