Earlier this week, the American Civil Liberties moved forward with a lawsuit filed in June, asking a New York court to stop the NSA from gathering any information from its phone lines while it attempts to end the agency’s mass metadata collection. "Calling patterns can reveal when we are awake and asleep," wrote Princeton professor Edward Felten in a briefing. "Our religion, if a person regularly makes no calls on the Sabbath, or makes a large number of calls on Christmas Day; our work habits and our social aptitude; the number of friends we have; and even our civil and political affiliations." Felten and the ACLU are trying to revive a case that Amnesty International lost earlier this year, hoping that the evidence is stronger this time around. But while we now know much more about the government’s surveillance efforts, the odds of convincing a court that anything’s changed are still slim indeed.

"I’m sympathetic to their argument, and I'm skeptical that the Supreme Court will endorse it."

Civil liberties groups have been locked in a legal battle over the Obama administration’s surveillance for years, but the ACLU is arguing that the leaked and declassified documents shed new light on a program that goes far beyond the letter of the law and the limits of the Constitution. "The government has collected every American’s call records for the last seven years, and it apparently intends to continue the program indefinitely," says the injunction filing. "That new technology enables the government to collect and analyze everyone’s information does not mean that the Constitution permits it." But it’s been stymied by the fact that the government won’t release details about its programs, making it almost impossible to tell who’s really being surveilled and to prove standing — that it was harmed by the program — in court.

"I’m sympathetic to their argument," says Columbia Law professor and former Supreme Court clerk David Pozen, "and I'm skeptical that the Supreme Court will endorse it." Last time around, the court was highly dismissive of Amnesty’s "speculation," something the Obama administration is playing up heavily. "There is no non-speculative basis to expect that queries of the metadata under this standard will return information about calls either made by plaintiffs, or made to them by others," it says. If the court orders it to give up records that could prove whether or not it’s specifically watching the ACLU, the administration can stonewall the request by saying it would compromise state secrets.

It’s also taken aim at the ACLU’s claim that collecting phone records has chilling effects on free speech. "Even if as yet unnamed third persons refrained from contacting plaintiffs out of fear that their association with plaintiffs could be revealed," it writes, "that would not constitute an injury attributable to the government’s actions."

Even if the ACLU wasn't targeted, widespread phone surveillance could still count as 'harm'

NYU legal expert Faiza Patel, though, has previously argued that proof of the NSA’s data mining could help a court case. "The steps they take to prevent collection … could be their ‘harm,’ if you will," she told The Verge in June. "They might need to spend money on particular types of technology to prevent this kind of data collection on their accounts." And the ACLU says that recently released documents give it good reason to believe the NSA is watching. According to a white paper, the NSA is allowed to access records for anyone within three degrees of a target, creating a web potentially much wider than the 300 queries the NSA says it conducted last year. If everyone involved communicates by at least 40 people, the ACLU says, those three hops could have encompassed 2 million people in 2012.

Courts will have to decide whether a 1979 law applies to present-day metadata

If the ACLU ends up convincing a court it was being surveilled — a big if — there’s still the question of whether collecting metadata counts as a real search. A 1979 Supreme Court case called Smith v. Maryland found that tracking phone numbers didn’t require a warrant, since it wasn’t a search protected by the Fourth Amendment. But police didn’t track how long Michael Lee Smith’s calls lasted, collect them over the course of months or years, or aggregate them with millions of other people’s call records. "The issue that's raised now is whether we're in a qualitatively different universe than what the court was thinking about in 1979," says Pozen — exactly the argument the ACLU is making.

The ACLU has an uphill battle to fight, but if it fails, future cases could do better. One of the best-case legal scenarios, Pozen said, would be someone filing suit after being prosecuted using phone metadata collected under the order: there’d be no question that they were being targeted, and being charged with a crime because of unlawful surveillance would clearly count as harm. For now, the case also raises questions that could have huge future implications — particularly on how we treat large amounts of metadata. "It's cutting-edge litigation, but it's going be very tough for the ACLU to win," he says.