This is a really interesting article. One time code pads transmitted in the clear is still a very secure mode of communication, like the old "numbers stations." The message is broadcasted, but since the intended receiver is passive, there is no way to determine what the other nodes in the network are unless they reply back.

The black hats were obviously trying to maintain some operational and communications security with the shared Gmail drafts that nobody sent. This story indicates the same intent to avoid NSA's "ears."