I like a good puzzle but I think this one is beyond my reasoning ability. Personally, I think it's a practical joke, someone messing with the folks at NSA and Homeland Security. However, maybe it's someone who wants you to think it's a joke so you'll not take it seriously. Good fodder for a suspense novel, though. If anyone wants to write it, I'll read it. Maybe a short story? (Credit to Joe Faust for the link.)
I will post something other than links to other sites soon. I promise.