Or copycat. People are fired from power companies all the time but how often do they damage equipment? I don't actually know but you'd think we'd hear about these attacks more.
Whilst uncommon, employee attacks aren't unheard of in any industry - or particularly unusual. The phrase 'going postal' originates in a period of time where being a postal worker was particularly stressful, causing many such incidents against management; but such attacks are background noise in most industries.