As someone who has worked in DOD and other classified programs, I realized what they were saying. Old NFO explains it as well as it can be explained. As they used to tell us in security briefings, just because something has been leaked and it's well known, doesn't mean it has been declassified. It would be illegal to look at the leaked data on the computer system they're talking about, because it's still classified and it's illegal to put classified material on that system. Yeah, insert obligatory talk about stupid rules here, but if you're an airman dealing with that stuff you often have to just say "rules are rules" and do what they say. Not only is Ft. Leavenworth federal prison not nice this time of year, it's never nice.
Instead of this being tyrannical, as Old NFO says,
"they are doing their folks a favor by preventing them from committing, however unwittingly, a security violation they would “legally” have to be prosecuted for."