The Snowden leaks were about the government secretly spying on people. These leaks include many topics, but a common theme is the government secretly pressuring companies to censor/punish users for saying anything that they did not approve of. And that approval was erratic, frequently targeting one of the first casualties of authoritarianism - humor. The leaks also tie in with this thread since as the the FBI also "requested" location tracking information on people as well, of course with no warrants or any sort of due process or oversight whatsoever. I look forward to one day reading the 'FBI files' to see how that information was then completely responsibly used.
Another revelation comes from your question itself. If you rely on mainstream media outlets to inform you, you'd either have no idea these 'leaks' exist, or a distorted view of what they contained. The NYTimes ran no less than 4 articles on 8 journalists being temporarily suspended on Twitter, promoting international regulations, laws, and even sanctions over it. But the entirety of these leaks, and the massive amount of content and information contained within? Well that's just not newsworthy contrasted against 8 journalists not being able to post on Twitter!
The media's independence and integrity has decline substantially since Snowden, with seemingly no bottom in sight.