The high court rules 5 to 4 that officers can arrest people who won't reveal their identity.
US citizens do not enjoy a constitutional right to refuse to reveal their identity when requested by police.
In what may become a major boost to US law enforcement and antiterrorism efforts, the US Supreme Court Monday upheld a Nevada law that makes it a criminal offense for anyone suspected of wrongdoing to refuse to identify himself to police.
Civil libertarians see the decision as a significant setback. And it remains unclear to what extent it may open the door to the issuing of national identification cards or widespread identity operations keyed to terrorist profiling at bus terminals, train stations, sports stadiums, and on city streets.
"It's a green light to explore the bounds of how much personal information can be demanded on pain of arrest," says Timothy Lynch of the Cato Institute in Washington. "It also gives a green light to perhaps the Congress to move with a national law."
Marc Rotenberg, executive director of the Electronic Privacy Information Center in Washington, says the decision has clear implications for the war on terror.
"We know identification continues to be one of the key demands of government agencies involved in homeland security," he says. "[This decision] - depending on how broad it is - could open the door to new demands for identification."
The ruling marks the first time the nation's highest court has endorsed a provision compelling citizens to reveal information in a citizen-police encounter that may become a police investigation.
The 5-to-4 decision says that neither the Fourth Amendment's right to privacy nor the Fifth Amendment's guarantee against self-incrimination bars states from passing laws requiring citizens to identify themselves.
In effect, the majority justices say that in most cases it is no significant intrusion for police to request - and a suspect to provide - his name.
"One's identity is, by definition, unique; yet it is, in another sense, a universal characteristic," writes Justice Anthony Kennedy for the majority. "Answering a request to disclose a name is likely to be so insignificant in the scheme of things as to be incriminating only in unusual circumstances."
Justice Kennedy adds that if a case arises in which the furnished identity provides a key link leading to the conviction of the individual for a different crime, the court will revisit the issue.