WASHINGTON -- U.S. Supreme Court justices this morning heard arguments from two attorneys addressing issues of animal cruelty and the First Amendment.

The case of the United States v. Robert J. Stevens, originating out of federal court in Pittsburgh, involves the sale and distribution of videos depicting dogfighting.

Mr. Stevens was convicted of three federal criminal counts but appealed his case to the 3rd U.S. Circuit Court of Appeals. In an opinion by that appellate court, the 1999 law under which Mr. Stevens was convicted was found to be unconstitutional because it impinged on free-speech rights. The government then appealed to the U.S. Supreme Court.

Today, Deputy Solicitor General Neal K. Katyal argued that the law in question was designed to dry up the market for so-called "crush" videos, which feature women in high heels crushing the heads of small animals.

"These are the most horrific images imaginable," he said.

Mr. Katyal acknowledged, however, in a question from Justice Ruth Bader Ginsburg that not one criminal case under this law had ever been filed in connection with crush videos. The reason, he said, is that after the law passed, the distribution of such videos stopped.

Free-speech advocates believe the law is hugely overdrawn and could affect images of hunting and fishing, as well as historical depictions of things such as bullfighting or Native American culture.

Advocates for Mr. Stevens also say the law leads to viewpoint discrimination. Animal protection groups, for instance, often use images of abused animals to raise awareness and to raise money, but none of them has ever been charged under the law in question.

"They're prohibited -- subject to the value police," attorney Patricia A. Millett, who argued on Mr. Stevens' behalf, said of selective prosecution in such cases. "It would all depend on what a jury decided."

Mr. Katyal argued that the 3rd Circuit erred because it did not evaluate the law to determine whether it is substantially overbroad. He suggested that the Supreme Court could add more nuance to it, to make the statute's meaning clear -- that it was designed to stop the sale of depictions of cruel and violent acts toward animals.

Washington correspondent Daniel Malloy writes the "Pittsburgh On The Potomac" blog exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.