These are great!
Loss of emotional control and violent oubursts are well documented among postal workers. There is even a phrase, "Going Postal", that describes this phenomenon.
It is a little known fact that there is a similar phenomenon that has been documented among the fishermen here on the coast of Maine. In the summer, when the plastic powerboats and sailboats are cluttering up the bays and harbors the poor fisherman is hard pressed to keep his gear intact. For some it is too much and the become violent, they go coastal.