571, 2003 SCC 74, is a Supreme Court of Canada decision that Parliament had the authority to criminalize the possession and trafficking of marijuana, and that power did not infringe on the section 7 of the Canadian Charter of Rights and Freedoms.

The Court found the harm principle is not a fundamental aspect of natural justice in Canada relevant to section 7 of the Charter.

In December 1996 the police raided the Harm Reduction Club and seized 316 grams of marijuana charging Malmo-Levine with possession for the purpose of trafficking.

Gonthier and Binnie looked towards R v Hauser, which held that narcotics were a new matter not considered in 1867 and so falls under the peace, order and good government power.

Three Justices, Louise Arbour, Louis LeBel, and Marie Deschamps, each authored individual dissenting opinions exclusively on the Caine case.