The FBI said on December 19 that the North Korean govenment hacked Sony:
As a result of our investigation, and in close collaboration with other U.S. government departments and agencies, the FBI now has enough information to conclude that the North Korean government is responsible for these actions.
Then on December 29th, Norse Corporation said this:
The investigators believe the disgruntled former employee or employees may have joined forces with pro-piracy hacktivists, who have long resented the Sony’s anti-piracy stance, to infiltrate the company’s networks. ...
Norse plans to fully brief the FBI on the current status of their investigation early this week, and says it is up to law enforcement to decide if there is enough evidence to pursue the individuals identified.
The disclosure casts further doubt on the FBI’s assertion that the attack was carried out by state-sponsored actors under the control of North Korea, a theory that has been all but discredited by a host of security professionals over the last week, including former federal prosecutor Mark Rasch.
Then on December 30 Politico said this:
After FBI agents were briefed yesterday, they concluded the security company offering the alternate theory did not have an accurate understanding of all the evidence, a U.S. official familiar with the matter told POLITICO today.
The three-hour meeting with FBI investigators yesterday by cyber intelligence firm Norse “did not improve the knowledge of the investigation,” according to the U.S. official.
So who is right? We still don't know. It would be nice to think the FBI is the top expert in this field. But that's not a given.
On the other hand, it is a given that the FBI has digital dossiers on all of us, so it's nice to think that they may actually use that to clear someone of wrong doing.