As the John Stagliano obscenity trial works through its third day of testimony, I think it's worth recalling one of the most famous sentences in legal history: Supreme Court Justice Potter Stewart's refusal to define "hard-core pornography" and willingness to deem materials the same.
The quote cames from a terrible 1964 case about a terrible movie called The Lovers (bad movies make bad law!). From Stewart's concurring opinion in Jacobellis v. Ohio that the movie was not hard-core porn and hence not actionable:
"I shall not today attempt further to define the kinds of material I understand to be embraced within that shorthand description; 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."
What a terrible standard (even if it did lead to an acquittal in this particular instance)! If you can't define something intelligibly, then you shouldn't have any right to lock somebody up for making that kind of movie.
The flicks that Stagliano distributes are indeed those kinds of movies (hard-core pornography). Why that sort of speech and expression is not given First Amendment protection is criminal. It was good to see the courts throw out the idiotic "indecency" standard recently. But as Jacob Sullum noted earlier, if indecency is unconstitutionally vague, then obscenity certainly is as well.