Poaching originally refers to the act of illegally snowboarding at a resort where snowboards are explicitly prohibited. Poaching is intended as a form of protest against what snowboarders view as segregation and can be seen as a form of civil disobedience.
Very few resorts continue to ban snowboarders. By definition, poaching is the practice of snowboarding where it is disallowed, usage of this term as a mean of protest is falling out of use as most resorts now allow snowboarding. In the United States only three resorts: Deer Valley, Alta Ski Resort (Both in Utah) and Mad River Glen in Vermont, continue to ban snowboarding. In contemporary usage, the term sometimes refers to skiing and snowboarding in out of bounds areas.