I actually had to Google "John Le Carre" - I had no idea who or what that was. I live a sheltered life, I guess.
How do we go forward?
I know one thing that should be implemented, right now.
Decentralize oversight. Get an oversight/IG office in each branch, way down below directorate level and where the worker bees are.
I don't care if you're gathering HUMINT, MASINT, ELINT, SIGINT, COMINT, whatever. Create oversight managers, train them in the mindset of protecting the U.S. Constitution and civil liberties, then put them to work.
You submit a request or start a new activity, that local oversight manager has to sign off on it - AFTER researching the legality thereof.
We all believe in the basic goodness of humanity, but my own experience after 20+ years in the IC is that there are way too many in those 3-letter organizations with somewhat faulty moral compasses.
They think they're doing Gawd's work. Hell, so did I. But in the pursuit of scoring the big jackpot, they get even more hungry. Moar. MOAR. MOAR. "We can do this thing, it's not as bad as they say it is, and it'll save lives!"
The collection capabilities of the U.S. Intelligence Community, if you've not been numbed to it by prolonged exposure, are mind-boggling, to say the least.
The day I retired, I signed a stack of non-disclosure paperwork, one clause that even forbade me from writing a book about my experiences until 75 years after I left.
Smart cookies, they are. They know I can't write that book from my dirt nap location.
At first I thought, "Well, hey, they're just protecting sources and methods". Maybe so, but they're also blocking the American public from knowing stuff that would really piss them off and rock the White House a hell of a lot worse than Snowden's piddly little disclosures.
Implement more stringent declassification guidance and schedules. We collect, classify, and hoard way more information than we discard.
There are supposed to be yearly reviews of material for downgrade or declassification. I say "supposed to" because it's in the guidance, the documents are even stamped with upcoming declassification dates or "OADR", but not always followed. The ten-year rule is a good one, if followed.
In my neck of the woods, that review happened only after driven by a FOIA request coming through the door, or some news event that made CNN or The New York Times.
"Classify and forget" seemed to be the mantra. Hell, there's there's still classified material about the ethnic tensions in Bosnia and Serbia during the Austro-Hungarian era, predating WW1. For Gawd's sake, why?
Revise whistleblower training, for both collectors and managers. Remove the stigma, and remove the friggin' retribution from doing so.
"We're collecting on American citizens, that ain't right!" should be met with action to stop that activity until it can be checked out for Oversight compliance, not an automatic categorization of "He's a terrorist, giving Al Qaeda the keys to 'Merrica".
Your life is essentially ruined for doing The Right Thing.
I didn't do the whistleblower thing, because I personally shut down many of those nascent collection ambitions and ideas, which I know for a fact torqued the agencies that thought they were the greatest thing since sliced bread.
That doesn't mean I'm in collusion with Al Qaeda. Nor am I talking Walker Spy Ring here. Those who would sell state secrets for financial gain, that's a different beast, bona-fide treason, and should be dealt with appropriately.
That ain't Snowden.
I hope the IC, not just the NSA, gets a thorough shake-down after the Snowden episode.