The increased training around the time of the Snowden-based leaks was largely focused around informing people who hold a national security clearance about the f

The increased training around the time of the Snowden-based leaks was largely focused around informing people who hold a national security clearance about the fact that information remains classified even if it has been published on the Internet. There was concern that people holding a national security clearance may use their unclassified information systems to process this (still classified) material, causing those machines to need to be treated at the highest classification of information on which they process (as they are not "periods processing" machines). Additionally the "need to know" principles still apply, and looking at classified information without satisfying that criteria could cause revocation of sponsorship for holding a national security clearance. The training likely stressed that just the source of the classified information was somewhere "outside" DoD it did not change the classification. This is because changing the classification requires an Declassification Authority to act on it, which is generally the Original Classification Authority -- of which there are very few.