The Supreme Court agreed Monday to decide whether to halt a legal challenge to a once-secret warrantless surveillance program targeting Americans' communications that Congress eventually legalized in 2008.

The announcement is a win for the Obama administration, which like its predecessor, argues that government wiretapping programs and laws can't be challenged in court.

At issue is the FISA Amendments Act, (.pdf) the subject of lawsuit brought by the American Civil Liberties Union and others, that authorizes the government to electronically eavesdrop on Americans' phone calls and e-mails without a probable-cause warrant so long as one of the parties to the communication is outside the United States. The communications may be intercepted "to acquire foreign intelligence information."

That bill was signed into law in July 2008, and the ACLU filed suit immediately. Then-senator and presidential candidate Barack Obama voted for the measure, though he said the bill was flawed and that he would push to amend it if elected. Instead, Obama, as president, simply continued the Bush administration's legal tactics aimed at crushing any judicial scrutiny of the wiretapping program.

After a surprise appellate court decision last year that reinstated the ACLU's challenge, the Obama administration asked the Supreme Court to overturn the decision. The government said the ACLU and a host of other groups don't have the legal standing to bring the case because they have no evidence they or their overseas clients are being targeted.

Without comment, the justices agreed to review the lower court's decision at a yet-to-be determined date. It marks the first time the Supreme Court has agreed to review any case touching on the eavesdropping program that was secretly employed in the wake of 9/11 by the Bush administration, and eventually largely codified into law four years ago.

A lower court ruled the ACLU, Amnesty International, Global Fund for Women, Global Rights, Human Rights Watch, International Criminal Defence Attorneys Association, The Nation magazine, PEN American Center, Service Employees International Union and other plaintiffs did not have standing to bring the case, because they could not demonstrate that they were subject to the eavesdropping.

The groups appealed to the 2nd U.S. Circuit Court of Appeals, arguing that they often work with overseas dissidents who might be targets of the National Security Agency program. Instead of speaking with those people on the phone or through e-mails, the groups asserted that they have had to make expensive overseas trips in a bid to maintain attorney-client confidentiality.

The plaintiffs, some of them journalists, also claim the 2008 legislation chills their speech, and violates their Fourth Amendment privacy rights.

Without ruling on the merits of the case, the appeals court agreed with the plaintiffs last year that they have ample reason to fear the surveillance program, and thus have legal standing to pursue their claim.

The Obama administration disagreed.

"Respondents' inability to show an imminent interception of their communications cannot be cured by the asserted chilling effect resulting from their fear of such surveillance," the government wrote (.pdf) the Supreme Court in a petition.

But even if the Supreme Court sides with the ACLU, that does not necessarily mean the constitutionality of the FISA Amendments Act would be litigated.

The lawsuit would return to the courtroom of U.S. District Court Judge John G. Koeltl in New York, where, if past is prologue, the Obama administration likely would play its trump card: an assertion of the powerful state secrets privilege that lets the executive branch effectively kill lawsuits by claiming they threaten to expose national security secrets.

The courts tend to defer to such claims. But in a rare exception in 2008, a San Francisco federal judge refused to throw out a wiretapping lawsuit against AT&T under the state secrets privilege. The AT&T lawsuit was later killed anyway, because the FISA Amendments Act also granted the phone companies retroactive legal immunity for their alleged participation in the NSA spying program.

The FISA Amendments Act generally requires the Foreign Intelligence Surveillance Act Court to rubber-stamp terror-related electronic surveillance requests. The government does not have to identify the target or facility to be monitored. It can begin surveillance a week before making the request, and the surveillance can continue during the appeals process if, in a rare case, the secret FISA court rejects the surveillance application.