While not quite as momentous as the legal tussle over the Pentagon Papers, in the ongoing push-pull between the First Amendment and national security, Twitter is taking an important stand against government overreach.

Last year, thanks to pressure brought by tech companies such as Google, LinkedIn and Facebook, the government relaxed the gag rules associated with national security-related warrants and subpoenas. But it still dictated exactly how much the companies could disclose about these requests.

Twitter, which has probably been the most aggressive of the major tech companies in pushing against these limits, argues in a suit it filed in federal court in San Francisco that it should be able to publish more detailed information about the requests, citing its First Amendment right to free speech.

This fight may seem a small matter given past battles between speech rights and government’s powers. The Twitter case does not raise the same grave matters as the Pentagon Papers, secret documents that described the history of American involvement in Vietnam, which were at the center of one of the most important free-speech cases in U.S. history. Nor is this as important as the current debates over the government’s broad crackdown on journalists reporting on counterterrorism efforts.

But the principle is the same: how to strike the balance between the free-flow of information in a democracy versus the need to keep some secrets from our enemies. And it comes in this post-Snowden world of ours, whose disclosures of National Security Agency surveillance have raised profound questions about the government’s efforts to monitor communications in its hunt for terror plots. In the wake of those disclosures, it seems to me that it’s more important than ever for us to have a better understanding of just what the government is up to in our name.

“Twitter’s efforts go to the core of informing the public what type of surveillance state we live in,” said Alex Abdo, staff attorney at the American Civil Liberties Union. “The government wants to have it both ways. It wants to conscript the tech companies to spy on their customers. But it won’t let them inform the public.”

The battle this time is in U.S. District Court for the Northern District of California, with the most recent development coming late last week when the government filed a motion to dismiss much of the Twitter case.

Like a lot of lawsuits, Twitter’s struck me at first as splitting hairs.

For example, when it comes to National Security Letters, an administrative subpoena that gives the FBI broad search powers, the government demands that Twitter disclose only how many it receives in increments of thousands; Twitter wants to disclose them in a more narrow range, by the one-hundreds. Likewise, when describing all national security requests, Twitter wants to talk about requests in groups of 25, not 250, as the government prescribes.

For its part, the government argues that there isn’t a free speech constitutional issue, and that it needs “to maintain the secrecy of information that could reveal sensitive investigative techniques and sources and methods of intelligence collection.”

I don’t pretend to know all the government’s concerns, and I acknowledge that all information comes with risks.

“It’s both harmful information to reveal and useful information,” said Eugene Volokh, a law professor at UCLA’s School of Law. “That’s the sad thing. The two things go hand in hand.”

But the government ought to have to prove why it needs to restrain speech.

“There have been many times over history that government has asserted secrecy was necessary,” said Kurt Opsahl, the deputy general counsel of the Electronic Frontier Foundation who recently argued on behalf of anonymous communications service companies in a related case before the 9th U.S. Circuit Court of Appeals.

But it has not always won, and I think the public was better served with the information that came to light. It’s hard to argue that release of the Pentagon Papers and what they disclosed about the U.S. and Vietnam was not a valuable addition to the public debate over the war.

Twitter’s challenge brings that battle to the modern era, allowing the court to decide “whether government’s need for secrecy survives a First Amendment review,” Opsahl said.

If the Internet services can’t talk about the scope and depth of government’s surveillance of online communications, our trust in them and the government will continue to weaken.

Contact Michelle Quinn at 510-394-4196 and mquinn@mercurynews.com. Follow her at twitter.com/michellequinn.