A well-known legal principle declares that ‘ignorance of the law excuses no one'. This maxim is used by legal systems throughout the world to impose constructive knowledge of the laws of the land upon those to whom such laws apply. Although exceptions have historically been made - for example by the Canadian courts in respect of hunters who were ignorant of a change of law that was made during the hunting season when they were hunting in the wilderness and, therefore, incommunicado - this generally means that a person cannot escape liability for violating a law on the basis that the content of that law was in fact unknown to that person.