U.S. immigration authorities acted constitutionally when they subjected dozens of people returning from an Islamic convention in Canada to screening tactics usually reserved for people suspected of being terrorists, an appeals court said Monday.

The court upheld the conclusion of a federal judge that the 2004 inspections, which involved frisking and fingerprinting, did not violate U.S. constitutional rights to practice religion and avoid unlawful searches.

"We do not believe the extra hassle of being fingerprinted and photographed — for the sole purpose of having their identities verified — is a significant additional burden that turns an otherwise constitutional policy into one that is unconstitutional," a three-judge panel wrote.

The New York Civil Liberties Union had sued on behalf of five New York residents who attended the "Reviving the Islamic Spirit" conference in Toronto. The NYCLU sought a court order to prevent similar inspections, along with destruction of personal information collected during the stops...

...The U.S. Bureau of Customs and Border Protection had received intelligence giving it reason to believe people with terrorist ties would be attending certain Islamic conferences during the 2004 year-end holiday season.

The court said the inspections were necessary because it was not possible for authorities to know who at the conference may have interacted and potentially exchanged identification or travel documents with people suspected of being terrorists...