why did the hon.bro.preznit say pyongyang did it?

cbsnews |  Fixing blame for cyber attacks is frustratingly difficult, partly because originators often employ proxies, partly because attack analysis turns up diversionary red herrings that implicate innocents. And that's just the start of the problem. 

It goes without saying by now that cyber weapons enlarge and blur understood definitions of war. Cyber aggressors include nation states, their private contractors, non-state evildoers, and corporate interests. There are no norms or conventions framing acceptable behavior in cyberspace -- the cyber version of arms treaties. There's no playbook for proportional retaliation, nor protocols for cooperative defensive action that join public and private interests. (As evidence of our own cultural confusion, some called news coverage of looted Sony data "near treason" -- as if the embarrassing email rants of studio execs are akin to nuclear launch codes.) 

Any rapid, unequivocal, on-the-record conclusion about who perpetrated what should raise eyebrows. This is especially true with Europeans, who harbor broad hesitation about such U.S. pronouncements after all those keenly recalled 2003 assurances about Iraqi weapons of mass destruction. 

Here the burden of proof is also high, and the skeptics are rightfully speaking up in greater numbers.