What struck me about the Snowden leaks, as opposed to previous (much smaller) leaks regarding the NSA is the fine grained insight into the apparatus, the machinery, and the scope of the spying. Whereas previously we only knew of vague scenarios like tapped undersea cables, we now know the specifics, mechanics, and even operational details of the NSA.

I think fine grained insight into what an intelligence service looks like on the inside is enough to compel people to change their behavior. I know for me, I was skeptical of claims the NSA even could do half the things people were purporting they could do, and having confirmation like this was the real game changer.