Assbandit: n. Literally, one who steals asses.
In colonial times, with dysentery being a far too common cause of death, a lucrative black-market arose around the trading of asses. A freshly harvested ass could sell for several pounds. Ass-bandits roamed the countryside, accosting travellers and making off with their asses.
In the Australian outback, so-called 'rumprangers' sometimes became local celebrities, and even national heroes. The most celebrated was Ned 'four-cheeks' Kelly, whose famous last stand involved him striding out to meet police in body-armour constructed entirely out of asses. Unfortunately, he soon discovered that the ass, as versatile as it is, is not bulletproof.
In America, local laws named this crime 'Highway Ass-Robbery', and thus the term 'Hershey Highwayman' was coined.