I see you’re right regarding Catholics view of sacred images . But I also see that there is a strict Catholic definition of blasphemy that does not include contempt toward people or objects in the Catholic Encylopedia on CD ROM : “While etymologically blasphemy may denote the derogation of the honour due to a creature as well as of that belonging to God, in its strict acceptation it is used only in the latter sense.”
Nothing in the South Park episode did that. Still, if you read through that page, you’ll see that simply claiming that God is an invention of man in blasphemy. Is that the blasphemy that you think government should outlaw or is it as I said earlier that blasphemy is a subjective term or at least an ambiguous term.
First, the plain definition of blasphemy for the courts cannot make distinctions that only theologians understand. So we either allow all blasphemy or ban all blasphemy, whether in the strict or in the popular sense.
Secondly, if the episode made fun of the plaster of the statue of Mary, that would be making fun of that which is of the created world. The episode, however, makes fun of the essence of her sainthood, -- her virgin womb. That is toughed by a miracle, in fact, by God in the very direct sense. So the blasphemy was also in the strict sense.
Historically, atheism -- the claim that God is an invention of man -- might have been considered blasphemy, but at the present age I would make an exception for such claims done in the spirit of philosophical inquiry when no obscenity is admixed tot he claim.