Glenn Greenwald did an AMA on reddit a while back where he was asked similar questions:
Q: I have to ask why the leaks are piece fed to the public? Why cant it be one big release? Thanks in advance.
Glenn Greenwald:
Many reasons:
1) It's irresponsible to dump documents without first understanding them and the consequences of publication.
2) It's 100% contrary to the agreement we made with our source when he came to us and talked about how he wanted us to report on them (if he wanted them all dumped, he wouldn't have needed us: he could have done it himself).
3) It would be impossible for the public to process a huge, indiscriminate dump, and media outlets would not care enough to read through them and report them because they'd have no vested interest in doing so (that's what WikiLeaks learned long ago, which is why they began partnering with media outlets on an exclusive basis for its releases).
4) The debate that we should be having would get overwhelmed by accusations that we were being irresponsible and helping the Terrorists; in other words, it would be strategically dumb to do.
5) There are already lots of risks for people reporting on these documents; there would be seriously heightened risks for anyone involved if they were just indiscriminately dumped.
http://www.reddit.com/r/IAmA/comments/1nisdy/were_glenn_gree...
Q: Out of the ones you have deemed to be worth releasing, what percentage of the Snowden documents have you released so far?
Glenn Greenwald: As I've said many times, there are thousands of documents, and the majority of ones that should (and will) be published still remain. Large numbers of people from around the world - including me and Laura Poitras - work every day as their primary or only occupation on getting these documents vetted, understood, and reported on as soon as possible.
http://www.reddit.com/r/IAmA/comments/1nisdy/were_glenn_gree...