One definition of the difference between terrorism and violent revolution is that revolutionaries choose instruments of the state as their targets – police, soldiers, government buildings and officials. Terrorists, whose goal is to terrify the populace into pressuring the government for change, attack ordinary people directly – the more ordinary and helpless the victims, the better targets they make from a terrorist's perspective.
According to that POV, Anonymous are not terrorists; they attack the financial, political and technical infrastructures that are the actual instruments those in power use to exercise that power.
The NSA doesn't have any firm reason to think Anonymous would attack the power grid. Its analysts just think Anonymous is turning in a more sinister direction, using Operation Global Blackout, apparently, as an example of the change. That reasoning – perfectly circular though it is to reach a conclusion based on misinterpreted evidence that seems most likely only in light of the conclusion someone reached because of it – seems tenuous.
It wouldn't be surprising if other players did – especially Iran.
Some factions within Anonymous might give utilities a try as well, for lulz if not with a solid political goal in mind.
But assuming Anonymous as a whole intends to attack and shut down the power grid just to make a point? Unless there's a reason that's actually valid to make anyone reasonably objective think it's true, I have serious doubts the Anonymi have causing major blackouts on their agendas, let alone on the list of confirmed well supported Operations.
Read more of Kevin Fogarty's CoreIT blog and follow the latest IT news at ITworld. Follow Kevin on Twitter at @KevinFogarty. For the latest IT news, analysis and how-tos, follow ITworld on Twitter and Facebook.