A group of 19 consumer and privacy groups today sued the National Security Agency (NSA), arguing that the agency's data collection processes violate the law and the Constitution.

The coalition is being led by the Electronic Frontier Foundation (EFF), which is no stranger to tangling with the NSA. In 2008, it sued the agency, President Bush, Vice President Dick Cheney, and several other administration officials on behalf of AT&T customers in an effort to stop the government's warrantless wiretapping program - a case that is still ongoing.

Today's filing - which also targets the FBI and Justice Department - is a companion to the 2008 case, EFF's legal director, Cindy Cohn, said during a Tuesday conference call with reporters. But it focuses on the more recent revelations about the NSA's data collection procedures, which were revealed in documents leaked by Edward Snowden to The Guardian and The Washington Post.

The first document published revealed that Verizon was ordered by the secret Foreign Intelligence Surveillance Court (FISC) to hand over all telephone records for its customers over a three-month period. That, in conjunction with the admission from James Clapper, director of national intelligence, that Section 215 of the Patriot Act allows for metadata collection on millions of Americans, is troubling, Cohn said.

Metadata collection "allows the government to learn and track the associations of ... organizations and their members," Cohn said, referring to the groups that have joined the lawsuit, like the First Unitarian Church of Los Angeles, Calguns Foundation, and the Bill of Rights Defense Committee.

If members of an organization believe their activity is being tracked, they will be less likely to join that group or reach out, Cohn said, so this widespread surveillance "creates a chilling effect," she said.

"The best way for this to end would be for President Obama to decide that he wants to stop the spying," Cohn said. "In the meantime, [we're] going to bring this matter before the courts."

The NSA, FBI, and other organizations have insisted that their programs are legal. But Cohn argued that since FISC proceedings are secret, there's really no way to know if that's the truth.

"We think the right place to determine whether the government is acting legally is in the public, adversarial court system," Cohn said. "Internal checks within the executive branch are not sufficient under law, and neither is a one-sided court process."

"Anybody can convince themselves that what they're doing is legal, but that's not how we work in this country," she continued.

The EFF is alleging that either the law doesn't authorize the NSA's activities, or if it does authorize that behavior, it's unconstitutional, Cohn said. "Frankly, I don't think [the NSA has] come clean at all about what they're doing."

The EFF is particularly concerned about the scope of the data collection. There have been two metadata-related cases in the past, but they were in the 1970s and they dealt with individual data collection, not a widespread "dragnet," Cohn said.

Cohn likened the NSA's program to the writs of assistance used by the British during the colonial era. The Brits "didn't have to specify whose information was collected; [they got] a general warrant that let them collect everything," Cohn said. The NSA's efforts are "the digital equivalent of writs of assistance. They were wrong in the colonial era and they're wrong now."

Given that the EFF is still fighting its 2008 case, Cohn was asked what chance this particular challenge has of making any headway. "The government has now admitted the telephone records program," Cohn said, pointing to Clapper's statement, so they can't hide behind the secrecy point, though they will likely try. But she acknowledged that there are "lots of immunities in the law that we're going to have to navigate." Constitutional cases are "always difficult."