Russians attacked power grid?

Remember this story?

(CNN) - An attack by snipers on a Silicon Valley power substation last year is prompting the former chairman of the Federal Energy Regulatory Commission to launch a crusade to better secure and defend the nation's electrical grid

[link to www.cnn.com]

Not to fear monger but is it possible that this was done by Russians? Maybe as a dry run to test u.s. grids in the case of a full blown war? Just connecting some dots here and brain storming.