Since the Snowden leaks first made clear the US government's sweeping database of phone call data, four separate legal challenges to that program have been filed in federal courts. Three of them now await decision from appeals courts.

This morning, a federal lawsuit directly challenging the NSA's vast phone call database was heard by the US Court of Appeals for the 9th Circuit. And the three-judge panel that heard Smith v. Obama seemed skeptical of the plaintiff's claims that the database should be ruled unconstitutional.

Anna Smith is an unusual plaintiff. In an interview last year with The Washington Post , she described herself as a "northern Idaho mom" with no particular legal background. "It’s none of their business what I’m doing—who I call, when I call, how long I talk... I think it’s awesome that I have the right to sue the president," Smith, then 32, told The Post. "I’m just a small-town girl."

Her husband Peter Smith, who argued the appeal this morning, is a commercial litigator with no experience handling a constitutional or national security lawsuit. For the appeal, Smith accepted legal help from the American Civil Liberties Union and Electronic Frontier Foundation, both of which have their own lawsuits challenging the NSA database.

Back to Smith v. Maryland

The government has long argued that it doesn't need a warrant to get phone "metadata" like the numbers called and duration of call. The main legal precedent it relies on is a 1975 case called Smith v. Maryland.

In today's argument, Peter Smith tried to differentiate his case from Smith v. Maryland.

"Smith v. Maryland involved a single defendant with a pen register on his phone for three days," said Smith. "Today, we have dragnet [surveillance] every single day. Tonight they'll download the call records, tomorrow they'll download the call records—and they'll keep them for five years."

The ability to analyze metadata has vastly improved as well, he noted.

"When you can do the hops, and see the connections—you can see that Anna called her doctor, Anna called her mother," he said. "It can reveal a lot about a person. It can reveal relationships."

That led to Judge Mary McKeown pointing out the government would still need to meet a "reasonable suspicion" standard.

Smith pointed out that would just be the second step, a legal guideline controlling how the NSA is allowed to search the database. In his view, the injury happened from the collection itself, which should be considered an illegal search barred by the 4th Amendment to the US Constitution.

US Circuit Judge Richard Tallman didn't seem convinced that Peter Smith had any evidence to justify overturning precedent.

"Why is Smith still not controlling?" asked Tallman, who also sits on the Foreign Intelligence Surveillance Court. "What is constitutionally significant about the data being collected today, versus the data that the Supreme Court approved in Smith v. Maryland? It appears to me it's the same data."

The scope of the program and the amount of the data make it fundamentally different, answered Smith.

"What if the government went to Verizon and said we want this data on everyone in the US for three days, would that be a [Constitutional] violation?" asked McKeown. "Yes," said Smith. "For one day?" asked McKeown. "Yes," he answered again. "And if they ask only for Ms. [Anna] Smith's data, is that a violation?" "No, not under Smith v. Maryland."

Seen this movie before?

When the government's lawyer Thomas Byron took the podium, US Circuit Judge Hawkins joked that "last time we were together, we were in a movie!" Hawkins, McKeown, and Byron were all featured in Citizenfour, the documentary about the Snowden leaks. That film included one scene with video from a different 9th Circuit case. "I guess we had no reasonable expectation of privacy," he joked.

Byron said he'd heard about the scene but hadn't seen the movie. The group then got down to business.

"Unlike Smith v. Maryland, you have a very different scope and duration," said McKeown. That changes the reasonableness calculus.

"One does and must expect that call information you provide to your telephone carrier will be made available over the entire time you use that carrier," said Byron.

Anna Smith can only mount a 4th Amendment challenge over her own data, not that of others, he added.

"What if the government wanted all utility records, nationwide?" asked Hawkins. "I don't know," Byron answered. "The 4th Amendment is context-dependent." "Well, hotel and motel receipts, then," Hawkins said. "This court has upheld an order to produce hotel records."

Byron also pointed out other cases limiting surveillance, like decisions leading up to the US v. Jones case that banned warrantless GPS tracking, carefully avoided disrupting the result of Smith v. Maryland.

Smith v. Obama is one of four lawsuits directly challenging the NSA's phone database; three of those cases are now awaiting decisions from different appeals courts. In ACLU v. Clapper, the government convinced a trial court judge to throw the case out; an appeal was argued in front of the 2nd Circuit in September. In Klayman v. Obama, the plaintiff won a preliminary injunction shutting down the NSA database. The DC Circuit heard that appeal in October.

A Northern California lawsuit organized by the Electronic Frontier Foundation, First Unitarian Church v. NSA, is moving more slowly, and that still awaits a final decision from the district court judge.

If any of those cases results in a win for plaintiffs, the NSA phone database will likely be headed to the US Supreme Court.