( AP )- The Supreme Court rejected a challenge Tuesday to the Bush administration's domestic spying program.
The justices' decision, issued without comment, is the latest setback to legal efforts to force disclosure of details of the warrantless wiretapping that began after the Sept. 11 attacks.
The American Civil Liberties Union wanted the court to allow a lawsuit by the group and individuals over the wiretapping program. The 6th U.S. Circuit Court of Appeals dismissed the suit, saying the plaintiffs could not prove their communications had been monitored.
The government has refused to turn over information about the closely guarded program that could reveal who has been under surveillance.
ACLU legal director Steven R. Shapiro has said his group is in a "Catch-22" because the government says the identities of people whose communications have been intercepted is secret. But only people who know they have been wiretapped can sue over the program, Shapiro has said.
The 9th U.S. Circuit Court of Appeals last year ruled against an Islamic charity that also challenged the program, concluding that a key piece of evidence is protected as a state secret.
In that case, the Oregon-based U.S. arm of the Al-Haramain Islamic Foundation alleged the National Security Agency illegally listened to its calls. The charity had wanted to introduce as evidence a top-secret call log it received mistakenly from the Treasury Department.
A separate lawsuit against telecommunications companies that have cooperated with the government is pending in the San Francisco-based appeals court. A U.S. district court also is examining whether the warrantless surveillance of people in the United States violates the law that regulates the wiretapping of suspected terrorists and requires the approval of a secret court.
A federal judge in Detroit declared the spying program unconstitutional in 2006, saying it violated the rights to free speech and privacy and the separation of powers. The appeals court decision that the Supreme Court upheld Tuesday resulted from the judge's ruling.
Several months after the judge in Detroit ruled against the Terrorist Surveillance Program, the administration announced in January 2007 that it would put intercepts of communications on U.S. soil under the oversight of the secret court, the Foreign Intelligence Surveillance Court.
The ACLU, in urging the justices to consider its case, said that because the administration voluntarily ended the warrantless wiretapping, it could easily restart it.
"There is a real risk that the president could decide he is not subject to the law," said Jameel Jaffer, director of the ACLU's national security project.
The administration acknowledged the existence of the program in late 2005, after the New York Times published an article about it.
The White House said the monitoring was necessary because the 1978 Foreign Intelligence Surveillance Act left dangerous gaps in the government's eavesdropping authority.
Last August, Congress made temporary changes to FISA that made the warrantless wiretapping legal in some instances and also extended immunity from lawsuits to telecommunications companies that help with the intercepts.
Those changes expired over the weekend, amid disagreements between congressional Democrats and President Bush over the immunity issue.
Existing wiretaps can continue and any new surveillance the government wants to institute has to follow the FISA rules, which could require court warrants.