The ACLU and Department of Justice sparred in court for the first time today over a lawsuit questioning the intelligence community's right to collect virtually all US phone records under counterterrorism laws. This morning, New York District Judge William H. Pauley III heard oral arguments for ACLU v. Clapper, a constitutional challenge to how the NSA interprets a controversial provision of the Patriot Act. Section 215, as it's known, lets intelligence authorities request "any tangible things" that are relevant in a foreign intelligence investigation.

In practice, it's used by the NSA to request phone records from all major telecoms and store them in a database, which is then searched for potential links between terrorists. But what the Obama administration sees as business as usual, the ACLU believes is an incredibly broad reading that violates free speech and subjects all Americans to unconstitutional searches. In response, it's asking for the court to stop the NSA from collecting any ACLU phone records while a full trial proceeds.

"You don't need all the call records for the government to do what it says it wants to do."

Today's hearing, meant to convince Pauley to either grant or dismiss that request, focused largely on two questions: whether Congress understands and agrees with how the NSA is interpreting its laws, and whether that interpretation violates the ACLU's constitutional rights, giving it standing to sue. Since Congress has reauthorized Section 215 multiple times and at least some legislators were briefed on how it was used, the Department of Justice insists that it's been given a strong mandate to proceed. The ACLU, meanwhile, points to explicit limits in the Patriot Act that say, for example, that the government bodies need to know "the identity ... of the person who is the subject of the investigation" before they go forward — knowledge the NSA clearly did not have. Pauley, however, didn't seem convinced by either of these arguments. He grilled ACLU deputy legal director Jameel Jaffer on whether the limits he was citing actually applied to Section 215, asking where he would draw the line at its scope and questioning his reading of the law.

He directed stronger barbs at Assistant Attorney General for the Civil Division Stuart Delery, poking holes in his claim that Congress understood what it was doing when it reauthorized the rule. While certain legislators, including Senator Ron Wyden (D-OR) and Dianne Feinstein (D-CA) were clearly privy to some details, many others either received no information or didn't seek it out. How could Delery argue that Congress had been fully briefed, asked Pauley, when "a classified document described in the program was not even made available to the House of Representatives in 2011?" Delery responded that the documents had been handed out in 2010 (which still meant that new representatives would never have seen them), then insisted that Congress had been given some classified FISA court opinions before they were released publicly in the wake of the NSA leaks, saying the intelligence community had made every effort to give context before Section 215's reauthorization vote. "You didn't succeed, did you?" said Pauley.

Regardless of Congress' intent, the ACLU argues that collecting a huge pool of metadata for millions of people goes far beyond a reasonable search. Phone metadata, including when, where, and who someone calls, can reveal when a person gets sick and calls the doctor, where they worship or attend other meetings, and much more. Collecting some information on a limited basis could be within the scope of the law, said Jaffer, but "you don't need all the call records for the government to do what it says it wants to do." The NSA has said it needs a ready database of all records so it can check suspicious numbers on short notice, but the ACLU says it could simply ask phone companies for specific metadata without compromising security or subjecting Americans to unconstitutional searches.

Judge Pauley seemed skeptical that some of the ACLU's legal gymnastics held up

The problem is that there's a widely accepted precedent for phone metadata: the 1979 Supreme Court case Smith v. Maryland says collecting it doesn't count as a search that might be protected by the Fourth Amendment. Civil liberties groups and some members of the current Supreme Court have questioned whether a 30-year-old rule covering one phone that was tapped for a few days should be applied to widespread, long-term surveillance, but Pauley seemed skeptical that there was another legal framework ready to fill its place. "If Smith doesn't control [the metadata rules], what rule should this court apply?" he asked ACLU staff attorney Alex Abdo. "At what point is phone-data collection no longer controlled by Smith?" Abdo countered that the question was irrelevant: no matter where that line was, bulk collection would cross it.

Pauley also questioned the ACLU's First Amendment defense: while Abdo said that clients might hesitate to call if they knew their phone records were being collected, the fact that they can't be sure those records will ever actually be seen — rather than filed away and forgotten — will make it tough to prove any real harm. Delery went further, saying that collecting the data wasn't any kind of search at all; in his estimation, nobody can credibly complain of an invasion of privacy unless they know the NSA actually queried their phone number. The ACLU argued that saying an almost unlimited phone record database is "relevant" opens the door to huge collections of medical records or other databases, but Delery scoffed at the idea, asking the court to trust the NSA's good judgment. "Potentially, the aggregation of the data can be a powerful tool," he said. "The key question is, who are you using it for?"

Pauley seemed more dubious that the NSA was acting responsibly, sparking a long discussion about what actually counted as relevant data. Delery, though, maintained that Congress knew exactly what it was doing by passing the rule. "It's authorized by law, and it's constitutional," he insisted. How can opponents even start changing Section 215? "Some other options are being debated in Congress," he said. "That seems like the place for those." So far, there's no hint of whether the ACLU's request to temporarily stop NSA data collection will be granted: Pauley is still considering the merits of both sides, and no follow-up court date has been set.