Silly squirrel, you know there is no leftist or Muslim violence in this country. It has to be those white supremacist Republicans.
It actually might be, for once, right wing violence. Big might, I still can't picture the goal they would be trying to achieve with such a localized and specific hit on AT&T. If there's a bunch more as specific it might signal something more organized, but sample size 1 here doesn't help.
Fired/laidoff /H1b'd exemloyee seems likely.
Way too low/avoiding collateral to really consider false flag shenanigans.
Insurance fraud or some sort of scam requiring the untimely destruction of company assets is plausible.
Evidence destruction is possible. Exactly what sort of hardware just got crispied?