On Monday a lawyer for the Crown argued that Canada's laws against possessing child pornography remain the best means of protecting children from sexual exploitation.
John Gordon's arguments to the three appeal court judges launched the Crown's bid to reverse a controversial lower court ruling that sparked national outrage last January.
John Robin Sharpe, a retired city planner, was acquitted of possessing child pornography. At the time a judge ruled that Canada's law prohibiting the possession of child pornography violated constitutional guarantees of freedom of expression in the Charter of Rights and Freedoms.
The decision led to angry protests about the protection of children and prompted an intense national debate.
Sharpe, who was in the court on Monday, listened as Gordon said the law enacted in 1993 remains a valid weapon against child pornography and the lower court ruling should be overturned.
"Many nations around the world have criminalized the possession of child pornography due to the harms children are put to by the production of this material", said Gordon.
John Dixon of the B.C. Civil Liberties Association says the law was rushed through in the dying days of the Tory government in 1993. "The problem with this law is that it is a dog's breakfast of the wish-lists of all of the Conservative forces that were swirling around Ottawa at that time."
Dixon says the law is too broad. "It includes products of the imagination - paintings, drawings, books and even advocacy of acts that are presently illegal."
The law also defines children as anyone up to the age of 18, even though 14 is the age of consent. Inside the courtroom Justice Mary Southin admitted she had trouble with that.
Southin asked Gordon if the law should apply to written material. She remarked on evolving social standards, noting the novel Lady Chatterley's Lover was seen as obscene in previous times.
But Gordon defended the law, saying society had drawn a line at material that could move pedophiles toward committing sex offences against children.
Over the next few days the court will also hear from the federal government, police associations and victim's organizations.