I've seen a a couple of attempts to investigate this. Obviously the set of "publicly accessible, yet classified information" is a weird set - I think some of t

I've seen a a couple of attempts to investigate this. Obviously the set of "publicly accessible, yet classified information" is a weird set - I think some of the Wikileaks information is technically classified sometimes newspapers publish information that is classified. I'm not aware of anyone who has noticed migration of this. > Often two unclassified statements can be brought together to form one statement that is classified. Classification usually relates to information providence so this is rarely true. It's true that two pieces of unclassified information can be used to derive knowledge that is also contained in classified sources though.