Isn't that kind of obvious to everyone at this point? It's just not out in the explicit open with the right kind of language. By giving such meager evidence of

Isn't that kind of obvious to everyone at this point? It's just not out in the explicit open with the right kind of language. By giving such meager evidence of a "certainty", they're essentially giving away that they determined this via other means. So, right now, let's assume it was a Russian spy agency that hacked the DNC. They're sitting there, thinking, "wow, these FBI folks somehow figured out it was us.". Then after reading this paper, "hmm, that's not a whole lot of evidence, they must have some proof that they're hiding. They must have a mole in our office. Find him, now."