For more context, it ruled out a false positive and pushed the boundary further, not vice versa:

I shall not today attempt further to define the kinds of material I understand to be embraced within that shorthand description ["hard-core pornography"], and perhaps I could never succeed in intelligibly doing so. But I know it when I see it, and the motion picture involved in this case is not that.

The Supreme Court of the United States reversed the conviction by ruling that the film was not obscene and so was constitutionally protected.

Absurdly, apple opponents itt use its completely opposite meaning in their arguments.