Imagine if the Centers for Disease Control, instead of researching cures for diseases, had a budget in the billions for buying weaponized viruses and bacteria, and was subverting disease prevention. Nobody would stand for that. It would be poisoning health care worldwide.
As another commenter pointed out here: "Can we just flip their budget over to making sure US companies are secure?" That is, of course, what should be done. We get the results we spend money on. If the NSA's budget were spent on making security easy and routine, we would have easy and routine security. But that's not how we express our intentions with the budget right now.
As another commenter pointed out here: "Can we just flip their budget over to making sure US companies are secure?" That is, of course, what should be done. We get the results we spend money on. If the NSA's budget were spent on making security easy and routine, we would have easy and routine security. But that's not how we express our intentions with the budget right now.