In very simple terms, basically the Supreme Court of Canada said that unless Parliament has specifically exempted you from a particular piece of legislation, if it's an offence for you, then it's an offence for me, unless I had been specifically exempted from it in legislation. They continued on to say that if Parliament wants you to go and commit a certain act or omission that would otherwise be an offence, they should then provide you with that exemption.
On May 30th, 2006. See this statement in context.