Official leaks v. unofficial leaks

Here's an article about restructuring of the US Army:

http://www.cbsnews.com/8301-201_162-57590979/army-to-cut-brigades-at-10-u.s-bases/

Please note the following sentence, which is usually found in all "official leak" stories:

Officials provided details on the plans on condition of anonymity because they were not authorized to discuss the matter publicly.

Someone please tell me, why is this leak about troop strength which DOES affect national security NOT treason, while Ed Snowdon's leaks about how the government is spying on its own citizens allegedly are treasonous?