By Canadians, by CBSA and others who would make it clear to them what the rules and provisions are of the Charter of Rights, the Bill of Rights, and the Human Rights Act. That creates the framework within which they function. They need to understand the terms of those fundamental laws, as well as the critical ways in which those laws may be different from the experience they may be used to in the United States.
On May 8th, 2017. See this statement in context.