Looks like a case of a whacko that believes the 5G bands are messing with his head, ran out of tin foil, so his only solution was to blow up the AT&T data center and himself as a solution to the problem.

Seems legit to me.

Either that, or he bought a new iPhone 12 and believed the TV hype about all the wonders of the wide-band 5G, only to discover that wide band 5G is basically available nowhere and available to no one and really isn't going to be widely available for another 3-5 years from now.

Or, he tried to ask out the AT& model/spokeswoman, got denied, and as a founding INCEL member, decided to blow himself and AT&T up.