The Supreme Court on Tuesday blocked a lawsuit challenging the federal government's monitoring of international phone calls and emails.
In a 5-4 decision that split along ideological lines, the court ruled that activists, journalists and lawyers represented by the American Civil Liberties Union (ACLU) could not prove that they were harmed by the wiretapping program.
"Simply put, respondents can only speculate as to how the attorney general and the director of national intelligence will exercise their discretion in determining which communications to target," Justice Samuel Alito wrote for the majority, agreeing with the Obama administration's position that the challengers lacked the legal standing to sue.
The challengers argued that because the government refuses to disclose specifics about the targets of its surveillance program, no one can prove whether they are being monitored.
They claimed that the program is likely collecting the private communications of people in the United States without proper judicial oversight, in violation of the Fourth Amendment.
The decision in Clapper v. Amnesty International did not address the constitutionality of the warrantless wiretapping program, which Congress authorized in 2008 as an amendment to the Foreign Intelligence Surveillance Act (FISA).
Congress enacted the legislation after details of the Bush administration's electronic spying program, which was intended to track terrorists, became public in 2005. The law grants the government broad powers to monitor private emails and phone calls as long as one of the parties is believed to be outside the United States.
The challengers included lawyers representing detainees in Guantánamo Bay. They argued that in order to prevent the government from intercepting their sensitive communications with foreigners, they had to take expensive trips overseas.
But the court's majority denied that such expenses qualified as a harm under the law.
"Respondents cannot manufacture standing merely by inflicting harm on themselves based on their fears of hypothetical future harm that is not certainly impending," Alito wrote.
Justices Stephen Breyer, Ruth Bader Ginsburg, Sonia Sotomayor and Elena Kagan dissented from the opinion.
Writing for the dissenters, Breyer argued that the harm was not merely speculative.
"Indeed it is as likely to take place as are most future events that commonsense inference and ordinary knowledge of human nature tell us will happen," Breyer wrote. "This Court has often found the occurrence of similar future events sufficiently certain to support standing."
ACLU Deputy Legal Director Jameel Jaffer, who argued the case before the court, called the decision "disturbing."
"The FISA Amendments Act is a sweeping surveillance statute with far-reaching implications for Americans’ privacy," he said in an email. "This ruling insulates the statute from meaningful judicial review and leaves Americans’ privacy rights to the mercy of the political branches."
—Updated at 5:12 p.m.