They pretty much don't ever want you to hear about them in the news. They don't want compromised entities to know they are compromised so they will keep reveali

They pretty much don't ever want you to hear about them in the news. They don't want compromised entities to know they are compromised so they will keep revealing sensitive information through the systems; they don't want specific vulnerabilities they are using to be known so they won't be patched, or even the general sorts of capabilities they have to be known; and at least traditionally it's thought like it makes the U.S. (or any other country) look bad to be breaking other country's laws and spying on them like this, when it's a country we theoretically aren't in hostilities with. It might make the attacked nations feel they have to retaliate in some way too, if it's public. Perhaps if the NSA focused more on defense instead of offense, they'd have been better able to protect our own government against this sort of attack. Who can say if some of the vulnerabilities used were ones the NSA in fact knew about but was keeping in it's pocket for it's own use. A well-resourced expert federal agency actually focused on security could make everyone safer from snooping; when they instead prioritize snooping themselves, they instead help make everyone less safe from snooping.