>I can't imagine how something like this, or Snowden's docs, could have leaked in the pre-internet days.
No imagination needed.
The Pentagon Papers, Deepthroat, Treaty of Guadalupe Hidalgo, the Hutchinson Letters, Mordechai Vanunu, and The Iran–Contra affair all predated the internet. Thats just off the top of my head.
I totally respect all of those examples on their merits, but IMO if these are the best examples out there, they all (even aggregated together as a single leak) pale in comparison to Snowden leaks.
1) I'm not sure that I agree with your judgement of the significance of those events.
2) Doesn't it stand to reason that papers that are more significant than those that were previously published are almost certain to be published, given that papers of lesser importance were published?
I wouldn't argue that the events weren't significant. They almost certainly captured just as many headlines as the Snowden leaks have. I'm mostly making a comparison between the information that was leaked.
Stakes are higher when there's more significant information to be published, so I would say it's not necessarily obvious to me that more significant information is more likely to be published.
Perhaps it will bring you clarity to understand that the first place this information was published was The Guardian. [0] It's a British newspaper that circulates physical papers, in addition to its Internet publication.
It's possible that in this day and age no US papers would have picked up the story, limiting its impact in the US. However, a story this large and important would have been picked up in the 1970's, just as the Pentagon Papers and other such stories were.
No imagination needed.
The Pentagon Papers, Deepthroat, Treaty of Guadalupe Hidalgo, the Hutchinson Letters, Mordechai Vanunu, and The Iran–Contra affair all predated the internet. Thats just off the top of my head.