For years, the government has successfully suppressed lawsuits by civil liberties groups challenging the constitutionality of its surveillance programs.
But the leaks by Edward Snowden have eroded the government's key legal defense and could mean that questions over whether the National Security Agency is breaking the law will be decided in open court.
"No matter what you think of the lawfulness of these programs, I think everyone should think their legitimacy or illegitimacy is better debated in public and decided by a court," Alex Abdo, a lawyer for the American Civil Liberties Union (ACLU), said.
The Justice Department has traditionally argued that groups like the ACLU and the Electronic Frontier Foundation (EFF) cannot prove that they have been affected by the surveillance, and they are therefore not in a position to challenge the programs in court—a legal concept known as "standing."
The courts have consistently sided with the government on the issue and, earlier this year, the Supreme Court threw out an ACLU lawsuit over warrantless wiretapping, concluding the group could not show it had standing to sue.
"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.
But the Snowden leaks have changed all of that. In response to a leaked court order, the NSA acknowledged that it is collecting data on all U.S. phone calls. The data collection includes phone numbers, call times and call durations, but not the contents of the conversations.
"For years, the government has shielded its surveillance practices from judicial review through excessive secrecy," Abdo said. "And now that that secrecy has been lifted to some degree, we now know precisely who is being surveilled in some of the dragnet policies of the NSA, and those people can now challenge those policies."
Thomas Moore, an attorney who is working with EFF on its case against the NSA, agreed that the civil liberties groups are now more likely to clear the standing hurdle.
"The Snowden revelations have shown that these gigantic dragnet programs are sweeping up everybody's data," Moore said. "It's not that difficult for us the plaintiffs to say, 'Everybody's data has been swept up. We are part of everybody, and so our data has been swept up.'"
But he cautioned that the groups are not "out of the woods."
The Justice Department filed a motion last month to dismiss the ACLU's lawsuit in New York, arguing that the group still has not shown it has standing.
The government asserted that although it collects data on all phone calls, it only targets a small number of phone numbers for analysis. Because the groups cannot show whether an NSA analyst actually reviewed their phone records, the groups cannot challenge the program, the government argued.
"Plaintiffs’ allegations of the consequences they will suffer as a result of the challenged intelligence-gathering activities depend on speculation that the Government has reviewed, or might in future review, call detail records of their communications, and that persons who would otherwise contact Plaintiffs by telephone may be 'chilled' from doing so by that conjectural prospect," the government wrote, arguing that "such speculation is insufficient" to establish standing.
But the civil liberties advocates argue the government is distorting the legal standard and that they should be able to challenge the bulk collection program, regardless of whether the NSA actually viewed their records.
"The Fourth Amendment has always been triggered when the government actually searches your information, no matter what it does with the information later on," Abdo said. "Under the government's theory, the NSA could record every phone call and copy every email so as long as it kept it in a database for later use."
Although the civil liberties groups have a new claim to standing to challenge the bulk collection of phone records, they may still struggle to sue over other more targeted surveillance programs that allow the NSA to listen in on calls and read emails. Because those programs do not affect everyone in the United States, it is more difficult for the groups to prove they have been affected.
"I think it's a much harder question with the other programs," Abdo admitted, adding that the ACLU is reviewing its legal options for taking on the other programs.
Moore argued that the civil liberties groups have the law on their side, but he expressed concern that the courts may be reluctant to strike down a program that government officials insist is critical to protecting national security.
"Courts behave oddly when national security is involved," Moore said.