Just because something is public or leaked does not automatically make it declassified. This material is still classified until officially declassified by appropriate classification authorities. Persons with a US security clearance should avoid viewing this material. I don't know what the NSA is telling its people. When I was a fed, before the Snowden leaks, we were already warned about not visiting Wikileaks, and to avoid viewing classified material outside of the proper facilities established for doing so (that meant the internet, for one).
Of course, if the government had its way, no one would view this material. But that's another discussion.
Of course, if the government had its way, no one would view this material. But that's another discussion.