Your quote about the NSA has nothing to do with criminal evidence.
Edit: badly worded.
But if what we're talking about is the idea that a clearly-defined Al Qaeda target operating in a territory that is self-evidently fertile ground for the operation of paramilitary death squads should somehow have been served with some kind of due process notification rather than being sniped from orbit, I'm less sure I'm on the same page with you.
For one thing, drone strikes kill far fewer people than ground operations do. Read any story about soldiers operating in middle eastern theaters (or Vietnam, for that matter) --- hell, read accounts of Army Ranger squads operating in theater --- and I think you'll see where I'm coming from. Somebody's old grandfather sticks his head out a window looking to see what the commotion is at the wrong time, and blam, he's a target. Ground combat (at least as long as it's conducted by humans on the ground) is necessarily horrific and anything that spares both sides those horrors is at least worth considering.
So that's a little shotgun blast of my thoughts about drone strikes.
As long as there have been states, there have been "non-state" actors that field real, no-shit militaries, with which to go to war.
The most famous example from history is the scourge of piracy on the high seas. You'll note that ships that would hoist the Jolly Roger would be treated with a military response, not a police one.
So, the legal framework for drone strikes against non-state belligerents is not nearly as nebulous as it's made out to be. In fact there's actually quite a bit of precedent within international law.
> Your quote about the NSA has nothing to do with criminal evidence.
It shows historical patterns of gross negligence in observing legalities by the Executive Branch that lead to things like killing your own citizens based on your own "evidence" without benefit of a trial.
It considers itself above the law to the point of being able to kill Americans without trial.
That aside, 40 years ago the NSA stated that it was above the law because it was created by Executive decree and tus not bound by statutory law:
"NSA does not have a statutory charter; its operational responsibilities are set forth exclusively in executive directives first issued in the 1950s. One of the questions which the Senate asked the Committee to consider was the "need for specific legislative authority to govern the operations of...the National Security Agency."
According to NSA's General Counsel, no existing statutes control, limit, or define the signals intelligence activities of NSA. Further, the General Counsel asserts that the Fourth Amendment does not apply to NSA's interception of Americans' international communications for foreign intelligence purposes." [1]
[1] Church Committee Report on NSA Surveillance Affecting Americans (1975)
https://news.ycombinator.com/item?id=5920793