I personally think Glenn Greenwald is piece of shit but that is beside the point. It doesnt matter what I think about whether or not the information in question should be exposed. As a person that has held a security clearance I can tell you this, it isnt for me to decide - That decision was way above my pay grade. I personally believe both Snowden and Manning should be imprisoned for a better part of the rest of their lives, but thats just me. They arent heroes, no matter how much you try to make that so. Its pretty egotistical of someone to believe they can see the bigger picture and know what the outcome of exposing that data will be. Data is classified for a reason and that decision wasn't made by you or I. It'd be even more maniacal of someone to decide the fate of others by exposing it which is what Assange, Snowden, Manning, and others have decided of their own volition to do.
That is a fair position. On the other hand, the people above your pay grade making those decisions are also deciding the fate of others. The distinction, of course, is that they have the legal legitimacy that you and I do not have.
But when those decisions go beyond the law, then that legal legitimacy can no longer be claimed, and they are just as egotistical for believing they can see beyond the lawmakers and courts. And unlike in the case of Assange, Snowden and Manning, we know their decisions have cost the lives of civilians, often children.
So as a citizen outside of the whole thing, I can only look at two groups of "maniacs" (to use your term) and be flabbergasted that we're even talking about the bad deeds of those three, let alone of only those three. If they deserve to be imprisoned for a better part of the rest of their lives, what does the other group deserve? Multiple life sentences?