Earlier quoted context omitted.
If the NSA's domestic spying is illegal, it's only on a technicality. Congress explicitly authorizes it, and the Supreme Court explicitly finds that the 4th amendment doesn't protect 3rd party records. I'm sure it's violated some specific regulations here and there, but on the whole, spying on everything everyone says and does is not illegal . Which is insane. It absolutely should be.
The 3rd Party Doctrine made sense when you were physically handing something to somebody else or whispering something in somebody else's ear. In today's world, its interpretation is ludicrously antiquated. Unfortunately, I don't forsee Congress doing much to solve this any time soon.
TL;DR - If congress made it "illegal" it wouldn't change anything. That they refuse to, will change everything.
Also, the third-party doctrine is sort of a recognition of the right the blow the whistle on crimes you see. It's not even (generally) a bad thing. It's only our government's too-cozy of a relationship with too much of the industry that means it's not whistle-blowing but twisted-arm leaks.