Nos anos 70 e início dos anos 80, houve alguns incidentes de violência no local de trabalho nos EUA, e o local de trabalho era o sistema postal local. Desde então, "ir postal" tem sido uma "coisa" de referência.
The expression derives from a series of incidents from 1986 onward in which United States Postal Service (USPS) workers shot and killed managers, fellow workers, and members of the police or general public in acts of mass murder. Between 1970 and 1997, more than 40 people were killed by current or former employees in at least 20 incidents of workplace rage.