The Supreme Court has declined to proceed with a challenge to the FISA Amendments Act (FAA), which controversially allows warrantless surveillance of American citizens and of others suspected of terrorism. In a 5-4 decision (PDF), the court determined that the civil rights groups who filed the suit do not have standing to do so, meaning that they couldn't establish a concrete or impending injury that would result from the suspected surveillance. Because of this, after nearly five years, this case will go no further.

"Respondents fail to offer any evidence that their communications have been monitored under §1881a."

The question of whether potential surveillance causes concrete harm has been central to whether the case proceeds. Critics of the FAA argue that particularly since the National Security Agency won't release any information on who is under surveillance, they've suffered chilling effects from reasonably believing that their communications have been intercepted when they make international calls or send emails. Though lower courts threw out that defense, the Second Circuit Court of Appeals overturned their ruling in 2011, and the Supreme Court said it would consider the case in mid-2012.

The NSA's refusal to release data creates a Catch-22 for critics of the law

In a majority opinion, Justice Samuel Alito rejected the notion that a suspicion of being surveilled was enough. "It is no surprise that respondents fail to offer any evidence that their communications have been monitored under §1881a," he writes, "a failure that substantially undermines their standing theory." The lack of evidence, however, is central to debates over the FAA. The NSA has refused to answer questions about the scope of its program, suggesting in a memo that investigating or revealing how many people were being monitored would "itself violate the privacy of U.S. persons."

A newly authorized FISA Amendments Act is set to run until 2017

It's a Catch-22 for opponents of the law. Alito said that the case was also complicated by the fact that even if the government was monitoring the plaintiff's communications, there was no way for them to guess that it was happening under FISA rules and not some other program. A dissenting opinion, issued by Justice Stephen Breyer, argued that the law made it significantly more likely that lawyers, human rights activists, or others involved in the case would be watched by the government. The court did not address the larger questions of whether the FISA Amendments Act was constitutional.

The original FISA Amendments Act was authorized in 2008, and Congress voted to approve it again in 2012; it will need to be renewed in 2017. Amendments that would require the NSA to estimate how many people it was monitoring or provide other safeguards were struck down.

Update: The ACLU has published a response condemning the dismissal:

Justice Alito's opinion for the court seems to be based on the theory that the FISA Court may one day, in some as-yet unimagined case, subject the law to constitutional review, but that day may never come. And if it does, the proceeding will take place in a court that meets in secret, doesn't ordinarily publish its decisions, and has limited authority to consider constitutional arguments.