That makes a good sound bite, but does it really make sense? Like if any ordinary citizen of a nation can access some information, isn't it pretty much a given that at least that much will be known to the nation's adversaries?
Some people's only frame of reference is that there's nothing "secret" that's of more import than that spreadsheet Katie from HR left out on her desk, and now OMG, everyone knows what everyone else makes, the horror . . .
I think that's why they invented compartments (Secure Compartmented Information), so that something could be classified at a lower level but compartmentalized, and that would make it take a lot longer to get into enemy hands. You weren't allowed to access something unless you had both the clearance level and had also been read onto that particular compartment, plus were able to show "need to know".
We were also told that just because something was printed in a newspaper, that doesn't mean it's unclassified. There were more than a few times when certain newspapers were banned in the building, because of an article that got printed that day.