Espionage is never legitimate unless you consider it acceptable for others to do it to you in the manner in which you do it to them. The hypocrisy of the NSA, CIA, GCHQ, BND, Mossad, FSB, etc. is grossly palpable. Everyone seems to do it, yet it's "shame on you" if anyone does it them. Pulling down the curtains was an important demonstration of collective, well deserved shame.
This crap belongs in movies and video games, not the real world. The citizenry of the world's nations should not be the game pieces used in the amusement and distraction of political and military rulers.
Those who can, do; those who can't, write. Those who can't write work for the Bell Labs Record.