While murky questions remained about the internet company program, the confirmation of the calling log program solved a mystery that has puzzled national security legal policy observers in Washington for years: why a handful of Democrats on the Senate Intelligence Committee were raising cryptic alarms about Section 215 of the Patriot Act, the law Congress enacted after the 9/11 attacks.
Section 215 made it easier for the government to obtain a secret order for business records, so long as they were deemed relevant to a national security administration.
Section 215 is among the sections of the Patriot Act that have periodically come up for renewal. Since around 2009, a handful of Democratic senators briefed on the program - including Ron Wyden of Oregon - have sought to tighten that standard to require a specific nexus to terrorism before someone's records could be obtained, while warning that the statute was being interpreted in an alarming way that they could not detail because it was classified.
On Thursday, Wyden confirmed that the program was what he and others have been expressing concern about. He said he hoped the disclosure would force a real debate about whether such sweeping, dragnet surveillance should be permitted - or is even effective.
But just as efforts by Wyden and fellow sceptics, including Senators Richard Durbin of Illinois and Mark Udall of Colorado, to tighten standards on whose communications logs could be obtained under the Patriot Act have repeatedly failed, their criticism was engulfed in a clamour of broad, bipartisan support for the program.
"If we don't do it, said Senator Lindsey Graham, "we're crazy".
And Representative Mike Rogers, the chairman of the House Intelligence Committee, claimed in a news conference that the program helped stop a significant domestic terrorist attack in the United States in the last few years. He gave no details.
It has long been known that one aspect of the Bush administrations program of surveillance without court oversight involved vacuuming up communications metadata and mining the database to identify associates - called a community of interest - of a suspected terrorist.
In December 2005, The New York Times revealed the existence of elements of that program, setting off a debate about civil liberties and the rule of law. But in early 2007, Alberto Gonzales, then the attorney general, announced that after months of extensive negotiation, the Foreign Intelligence Surveillance Court had approved innovative and complex orders bringing the surveillance programs under its authority.
Sign up for CIO Asia eNewsletters.