Terrorists take aim at PG&E. Can it shield itself?

Terrorists would like nothing better than to bring down Silicon Valley in one fell swoop. One way is to cut off its electric power. But PG&E is arming itself, too.

http://www.csmonitor.com/Environment/Energy-Voices/2014/0705/Terrorists-take-aim-at-PG-E.-Can-it-shield-itself