....which would basically mean everything not subject to local laws; ie made in foreign countries?

I'm assuming you would agree for some electronic material. How do you pick and choose which should be forced to follow the law?

The legal system has a well developed notion of jurisdiction to del with that. A movie shot in California will follow California’s laws on child labor, not New York’s, even if it’s shown there.

It is not consistently applied. Look at bans on obscenity regardless of the legality where or when it was produced. So it seems just as reasonable to say that local ISPs are responsible for blocking locally illegal material.