No kidding. The phrase “going postal” came about from postal employees going postal.
George: Let me ask you something: what do you do for a living, Newman?
Newman: Why, I'm a United States postal worker.
George: Aren't those the guys who go crazy and come back with a gun and shoot everybody?
Newman: Sometimes.
Jerry: Why is that?
Newman: Because the mail never stops. It just keeps coming and coming. Piles of it, more and more! And you have to put it all out, but the more you put it out, the more it keeps coming in! And then the barcode reader breaks! And it's Publishers Clearing House Day!...