First, ordering the attack of homes with no regard for civilians nearby and no concrete proof that someone "bad" is inside is fairly unequivocally atrocious. I think if your loved ones died because the NSA assumed a bad guy lived next door, you'd consider it an atrocity.

Second, I consider lying to spread more warfare and all the horrors that entails atrocious.

The Vietnam War.

That's preposterous.

You think My Lai was justified and not an atrocious war crime? How about Agent Orange?

https://en.m.wikipedia.org/wiki/United_States_war_crimes#Vie...

What is the most atrocious thing that the NSA has done?

No idea, but the thread above is about the Gulf of Tonkin incident. Snowden revealed quite a bit of execrable behavior, and quite a bit of historical bad behavior has been revealed over time. They are certainly not paragons of righteousness and purity.