This looks like another case where the actions of the NSA are the opposite of what's in the best interest of US Citizens.
Yes, and quite easily.
If that's your only testing criteria for whether a government agency is useful then NSA will pass with flying colors.
Anyway lets skip the banal "intelligence agencies failures are public and the successes are private" and get to actual examples:
DES SBoxes
SELinux
NSA Academic Centers of Excellence
VENONA
I assume what you really mean is whether their dragnet surveillance in particular is ever beneficial to US citizens, and that certainly seems to be a "no".
Their job is to keep us safe.
Letting us all run around with humungous holes in our security for years was a risk to our national security. How do you think the Chinese were able to clone our weapons systems so well? Shit like this.
NSA is a spy agency, expecting them not to use vulnerabilities they find is like sending them into a gunfight with a pocketful of rocks. Ask the Palestinians how that works out in the long run.
I think much of the NSA's surveillance is unconstitutional and should be rolled back by at least 2 orders of magnitude. That doesn't have to entail turning the world over to Russian and Chinese hackers.
That's exactly what they do when they allow bugs like this to continue to exist, rather than working to fix holes, not exploit them.
Boogey man FUD, I'm not worried about any hackers from [Insert_forgein_country_elites_want_you_to_hate]. The USgov, NSA and corrupt law enforcement are the only terrorists I'm worried about.
Why? Nations have track records of not killing/spying on each others?
It's reasonably to be suspicious of government.
Why do we let awful people like this be in charge of our well being? Is power too entrenched that no matter what happens, we can't do anything about it?
Spying on the country and spying on behalf of the country are not really the same thing.
Who gets to decide whether the risk is acceptable? To whom do we turn to when it's found that their risk assessment was flawed, and we require compensation for their recklessness and negligence?
The only way to get a different result is to re-allocate resources away from NSA and build an agency from the ground up that is geared toward securing systems.