The NSA lost its authority to carry out its bulk data collection program after Senator Rand Paul blocked efforts in the Senate on Sunday to extend it. Two other provisions of the law that authorities use to track terror suspects were also allowed to lapse.
As of today, security and intelligence officials can't collect the phone data and also can't get a roving wiretap that allowed them to monitor suspects who frequently changed devices. Now they will need to get individual warrants for each phone or device a suspect is using.
The so-called "lone wolf" provision of the Patriot Act also expired, a tool that helped authorities track suspects with no connections to foreign powers. It had never actually been used.
The House of Representatives passed a bipartisan bill, the Freedom Act, that would reform the data collection program and leave the other two programs intact. The Senate debated it on Sunday as the midnight deadline approached, and Paul, who is running for the 2016 Republican nomination, prevented a final vote.
The Senate is expected to pass the bill in the coming days, but until then the NSA can't carry out the three programs. There are mixed opinions on how serious this is and what effect it has on national security.
U.S. 'absolutely' at risk
White House Press Secretary Josh Earnest was asked repeatedly on Monday if the American people are less safe. He said that's a "judgment call" that he would prefer the country's top security and intelligence authorities to comment on and that he would let people draw their own conclusions.
But Earnest did say that the Patriot Act provisions had been valuable tools for security authorities and now they don't have those tools at their disposal.
"Why would we add unnecessary risk to the country and our national security because of Congress's failure to act?" said Earnest.
In his weekly address on Saturday, Obama called it a matter of national security and warned about the risk. "Terrorists like al-Qaeda and ISIL aren't suddenly going to stop plotting against us at midnight tomorrow. And we shouldn't surrender the tools that help keep us safe. It would be irresponsible. It would be reckless, and we shouldn't allow it to happen," he said.
Obama quoted FBI Director James Comey, who said allowing the Patriot Act authorities to lapse would "severely" impact terrorism investigations.
CIA Director John Brennan, interviewed on Sunday on CBS's Face the Nation, said the law has been important to American lives and helped stop terrorist attacks.
"The tools that the government has used over the last dozen years to keep this country safe are integral to making sure that we're able to stop terrorists in their tracks," he said.
Accusations of fear-mongering
On another Sunday talk show, on Fox News, retired general Michael Hayden, former head of the CIA and the NSA, was asked whether the U.S. is in greater danger now.
"Absolutely," he answered. "Why would we give up things the professionals say keep us safer?" He said the NSA programs are all threads in a fabric that protects Americans.
Expressions of concern about national security are not necessarily falling along party lines. Jeb Bush, expected to become a 2016 Republican presidential candidate, said he believes the country is at a greater risk without the NSA programs being active and that they should have been re-authorized.
George Pataki, who has already entered the 2016 Republican nomination race, said American lives are at risk "for political reasons."
"We are at as great a risk today as we have been at any time since Sept. 11 of another terrorist attack," he said on CNN.
But Paul doesn't buy these arguments and neither do other privacy advocates who think the NSA's surveillance infringes on Americans' civil liberties.
"The people who argue that the world will end and we will be overrun by jihadists tonight are trying to use fear. They want to take just a little bit of your liberty, but they get it by making you afraid," he said during the debate Sunday night.
Paul believes the bulk data collection is illegal, a position that was supported by a recent court ruling, and that it hasn't even been useful in catching terrorists.
The American Civil Liberties Union says intelligence agencies have been "fear-mongering." The ACLU further argues that the NSA programs are ineffective and there is no proof they've worked to deter terrorism. Instead, the ALCU says, the government gets to glimpse into the private lives of citizens and it has "nothing to do with national security."
Paul and the ACLU say the government still has the ability to monitor terror suspects and protect Americans without the Patriot Act, including getting warrants from judges for surveillance.