A. International Conventions In 1949, members of the international community signed the United Nations (UN) Convention for the Suppression of Traffic in Persons and Exploitation of the Prostitution of L I B R A R Y. O F. P A R L I A M E N T B I B L I O T H È Q U E. D U. P A R L E M E N T 2 Others(1) (1949 Convention), which states in its preamble that “prostitution and the accompanying evil of the [...] In 1999, the international community returned to the issue of children’s rights in the International Labour Organization’s Convention concerning the Prohibition and Immediate Action for the Elimination of the Worst Forms of Child Labour.(12). [...] These are the obligations to which Canada has committed itself (although it has yet to ratify the final Optional Protocol to the Convention on the Rights of the Child on the Sale of Children, Child Prostitution and Child Pornography), and they are reflected in Canadian law. [...] Federal jurisdiction over the criminal law is derived from s. 91(27) of the Constitution Act, 1867, which states that the powers of Parliament include: “[t]he Criminal Law, except the Constitution of Courts of Criminal Jurisdiction, but including the Procedure in Criminal Matters.” (15) According to the Vienna Convention on the Law of Treaties (UN Doc A/Conf 39/28 1969), a presumption of good fait [...] Evidence that a person lives with or is habitually in the company of a prostitute or lives in a common bawdy-house is, in the absence of evidence to the contrary, proof that the person lives on the avails of prostitution.