We need something more fundamental. Like it never being against the law to disclose information on crimes committed by intelligence agencies, and enforcement of existing laws once those crimes come to light: for example, Keith Alexander needs to be arrested for perjury. Perhaps we could bring back private prosecutions... that would certainly go a long way towards ensuring public officials are not above the law.
This more holistic approach is necessary because the usual suspects (CIA, NSA) and the usual frameworks (FISC) only capture a tiny fraction of what the intelligence community actually engages in. Take the NRO (
https://en.wikipedia.org/wiki/National_Reconnaissance_Office ) for example. It has a comparable budget to the more well known agencies and they were even caught by the CIA to be squirrelling away extra money, presumably to finance black projects. They started in spy satellites but these days they appear to devote a significant portion of the resources towards hacking. They really put the NSA to shame when it comes to blackhat and grayhat activities, though good luck finding anyone to confirm that for you. Let's just say they appear to enjoy inspiring awe and fear in their employees, to the point where though I've met several people who worked for them I had to do a considerable amount of detective work and deduction to figure it out. And even then there was no explicit confirmation I was right, just a wry smile and a "I can neither confirm nor deny..."
And that's just an agency we know about. Like the NSA before it, the NRO used to be secret. And there remain still more secret intelligence agencies today, probably even more fearsome and powerful than the public ones. And if you think these guys go through FISC every time they feel the urge to skim through someone's inbox...
So, back to my original point: what we really need here is a mechanism to permit the discovery and prosecution of people who conceal crimes, both for the original crime and for the act of covering it up by claiming state secrets. Crimes like lying to congress under oath. Or spying on American citizens, without judicial oversight, in ways that would be illegal if a private citizen did it (which does not necessarily apply to PRISM but most certainly applies to other programs.)