Does "Conan the Barbarian" have serious artistic value? That's one of the intriguing questions raised by a case the U.S. Supreme Court will hear next Tuesday.

Because "Conan" includes footage of horses tripped by wires, it is arguably covered by a federal ban on depictions of animal cruelty.

If so, Amazon is committing a felony by selling it, unless it could convince a jury that the 1982 epic -- in which a bare-chested, codpiece-wearing future governor of California declares that the best thing in life is "to crush your enemies, see them driven before you and hear the lamentation of their women" -- has "serious religious, political, scientific, educational, journalistic, historical or artistic value."

By inviting jurors to be film critics, with the consequences of a bad review including up to five years in federal prison, Congress has turned the First Amendment on its head. That lamentation you hear is the dismayed cry of the Framers at the blitheness with which the people's representatives seek to crush expression that offends them and drive politically incorrect thoughts from the realm of tolerable discourse.

Back in 1999, outraged by videos aimed at people who get a sexual thrill from watching women stomp on little animals, Congress made it a felony to create, sell or possess with intent to distribute a "depiction of animal cruelty." It defined the forbidden material as any visual or audio record of conduct that hurts an animal when the conduct is prohibited by federal law or the law of the state where the depiction is created, sold or possessed.

Although President Clinton said when he signed the law that it should be used to prosecute people only for material akin to the "crush videos" that provoked it, all three cases brought so far have involved footage of dogfights. In the case before the Supreme Court, Robert Stevens, a Virginia pit bull enthusiast, received a three-year prison sentence for selling two videos showing pit bulls fighting and one showing them hunting wild boar.

Stevens' conviction demonstrates how the ban on depictions of animal cruelty can send people to prison based on jurors' subjective reactions to a film. Stevens says he does not endorse dogfighting but used footage of it -- shot in Japan, where the sport is legal, and in the United States more than three decades ago -- to illuminate the history and behavior of pit bulls. Defense experts testified that the videos, which are far tamer than images routinely used by animal rights activists to rally support for their cause, have substantial educational, historical and scientific value.

The prosecution's experts disagreed, quibbling over matters such as the length of certain scenes and Stevens' decision to illustrate poor training by showing a dog attacking a domestic pig. In 2006, the U.S. Court of Appeals for the 3rd Circuit overturned Stevens' conviction, ruling that Congress had violated the First Amendment by making a man's liberty hinge on such unpredictable, arbitrary judgments about the value of his speech.

The appeals court noted that "the statute potentially covers a great deal of constitutionally protected speech," including images of bullfighting in Spain (since the recorded conduct need only be illegal where it is possessed or sold) and of hunting or fishing out of season.

Similarly, in a brief asking the Supreme Court to uphold the 3rd Circuit's ruling, several journalism organizations that worry about the law's impact on coverage of animal-related issues say it "appears to be a felony for anyone in Oregon to possess depictions of legal, licensed crossbow hunting in Washington." Wrinkles like that could imperil the entire genre of hunting and fishing videos.

Solicitor General Elena Kagan suggests the Justice Department will avoid such bizarre results by applying the statute judiciously. But Stevens' prosecution, which goes beyond the avowed intent of Congress, shows the department cannot be trusted to do so. If the First Amendment means anything, it means freedom of speech should not depend on prosecutorial discretion.