The justices heard arguments Monday in a first-of-its kind case that asks whether people can be punished for refusing to identify themselves.

The court took up the appeal of a Nevada cattle rancher who was arrested after he told a deputy that he had done nothing wrong and didn't have to reveal his name or show an ID during an encounter on a rural road four years ago.

Larry "Dudley" Hiibel, 59, was prosecuted, based on his silence, and finds himself at the center of a major privacy rights battle.

"I would do it all over again," Hiibel, dressed in cowboy hat, boots and a bolo tie, said outside the court. "That's one of our fundamental rights as American citizens, to remain silent."

The case will clarify police powers in the post-Sept. 11 era, determining if officials can demand to see identification whenever they deem it necessary.

Nevada senior deputy attorney general Conrad Hafen told justices that "identifying yourself is a neutral act" that helps police in their investigations and doesn't — by itself — incriminate anyone.

But if that is allowed, several justices asked, what will be next? A fingerprint? Telephone number? E-mail address? What about a national identification card?

"The government could require name tags, color codes," Hiibel's lawyer, Robert Dolan, told the court.

At the heart of the case is an intersection of the Fourth Amendment, which protects people from unreasonable searches, and the Fifth Amendment right to remain silent. Hiibel claims both of those rights were violated.

Justice Antonin Scalia (news - web sites), however, expressed doubts. He said officers faced with suspicious people need authority to get the facts.

"I cannot imagine any responsible citizen would have objected to giving the name," Scalia said.

Justices are revisiting their 1968 decision that said police may briefly detain someone on reasonable suspicion of wrongdoing, without the stronger standard of probable cause, to get more information. Nevada argues that during such brief detentions, known as Terry stops after the 1968 ruling, people should be required to answer questions about their identities.

Justice Sandra Day O'Connor (news - web sites) pointed out the court never has given police the authority to demand someone's identification, without probable cause they have done something wrong. But she also acknowledged police might want to run someone's name through computers to check for a criminal history.

The encounter in this case, which was videotaped, shows Hiibel by a pickup truck parked off a road near Winnemucca, Nev., on May 21, 2000.

An officer, called to the scene because of a complaint about arguing between Hiibel and his daughter in the truck, asked Hiibel 11 times for his identification or his name.

Hiibel refused, at one point saying, "If you've got something take me to jail" and "I don't want to talk. I've done nothing. I've broken no laws."

Hiibel never acted in a threatening manner and cooperated when handcuffed. His daughter, a teenager at the time, was thrown to the ground and arrested when she protested his arrest, the video shows. She was not convicted of any crime.

Hiibel was convicted of a misdemeanor charge of resisting arrest. He was fined $250.

Nevada is supported by the Bush administration and two criminal justice groups. Organizations backing Hiibel include the American Civil Liberties Union (news - web sites), the Cato Institute, privacy groups and advocates for the homeless.

Marc Rotenberg, president of the Electronic Privacy Information Center, said if Hiibel loses, the government will be free to use its extensive data bases to keep tabs on people.

"A name is now no longer a simple identifier; it is the key to a vast, cross-referenced system of public and private databases, which lay bare the most intimate features of an individual's life," Rotenberg told the court in a filing.

The case is Hiibel v. Sixth Judicial District Court of the state of Nevada, 03-5554.

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