(CNN) -- Details on millions of American phone calls. Records of e-mails, texts, video chats and more from overseas. And pulsing beneath it all, a worrying concern there's more to the government's surveillance programs than what's been acknowledged.
All the revelations about U.S. surveillance programs in recent days have put the government on the defensive, set privacy advocates howling for reform and left millions of Americans somewhere in the middle, wondering what the news means to them and what, if anything, they should do about it.
The man at the top says they should just relax.
"Nobody is listening to your telephone calls," President Barack Obama said Friday as he tried to reassure Americans who have had to digest a dizzying array of revelations in the past few days. Among them:
-- U.S. intelligence agencies are, in fact, collecting details on just about every telephone call placed each day in the United States, U.S. officials confirmed. And they've been doing it for seven years, a senator added.
-- They're also monitoring the online activities of at least some overseas customers of Google, Microsoft, Yahoo, Apple and other providers of popular online services.
-- And they may be scooping up credit card data, as well, The Wall Street Journal reported Friday, citing people familiar with the operations of the National Security Agency.
U.S. officials say the phone-call data isn't looked at unless investigators sense a tie to terror, and only then on the authority of a judge. And officials say analysts are forbidden from slurping up the Internet activity of American citizens or residents, even when they travel overseas.
The Wall Street Journal said it wasn't clear whether the credit card monitoring was a continuing program or a one-off, and didn't say what analysts did with the information.
Analysts say such information can be analyzed using powerful computers and sophisticated software to detect personal habits and links among groups of people, and to build detailed dossiers on the activities of everyday people.
The government says it is not doing that, but privacy activists say even the limited amount of data collection U.S. officials have acknowledged poses huge threats.
"The problem is its massive surveillance," said author James Bamford, who has written extensively about NSA surveillance programs. "We went through this problem with the Bush administration, warrantless eavesdropping. It was an outrage that government can turn the surveillance on average citizens without any suspicion whatsoever."
"And here, this is an enormous increase in that," he said on CNN's "Erin Burnett OutFront" on Thursday. "This is communications that are local. These aren't even international communications at all. These are communications from people speaking to their neighbors, people that are under no suspicion whatsoever."
The American Civil Liberties Union described the programs as "beyond Orwellian."
And the Electronic Frontier Foundation, which has been fighting the government over surveillance programs for years, is urging a full-scale investigation with an eye toward stopping the surveillance programs for good and reining in U.S. intelligence agencies with new laws and a demand for public oversight.
"The revelations not only confirmed what EFF has long alleged, they went even further and honestly, we're still reeling," the privacy organization said Friday on its blog.
The revelations began Wednesday, when a British newspaper, the Guardian, published a top secret order from an intelligence court that required Verizon Business Network Services to give telephone records detailing the time, location and telephone numbers involved in domestic calls from April 25 to July 19.
The Electronic Frontier Foundation and other analysts said similar orders undoubtedly are in effect for other companies.
The order doesn't allow authorities to listen in on the calls.
National Intelligence Director James Clapper, who denied during a March 12 congressional hearing that the government was engaged in mass data-collection practices involving Americans, blasted the Guardian report, saying it "omits key information" regarding "safeguards that protect privacy and civil liberties."
He said the program operates within the law, respects Americans' privacy and is crucial to preventing attacks. Most of the records are never looked at, and those that are can be reviewed only with judicial approval, he said.
"The collection is broad in scope because more narrow collection would limit our ability to screen for and identify terrorism-related communications. Acquiring this information allows us to make connections related to terrorist activities over time," he said.
Clapper said both Congress and courts have reviewed and authorized the law.
But several congressional critics have complained that the government has made significant use of broad interpretations made in secret by the Foreign Intelligence Surveillance Court, the judicial body charged with overseeing the government's use of the law.
"These reports are deeply concerning and raise questions about whether our constitutional rights are secure," Patriot Act co-author Rep. James Sensenbrenner wrote in a letter to Attorney General Eric Holder.
Sensenbrenner, a Wisconsin Republican, said he was "extremely disturbed by what appears to be an overbroad interpretation of the act."
A day after the initial Guardian report on the Verizon court order, the Guardian and the Washington Post published reports alleging the NSA is able to tap into data held by some of the world's biggest online services companies as it hunts for terrorists.
The program, which the newspapers said is called PRISM, reportedly allows NSA analysts access to computers at Microsoft, Google and other companies to extract details of customer activities, including "audio and video chats, photographs, e-mails, documents" and other materials, The Post reported.
The Post reported PRISM, founded in 2007, has become the leading source of raw material for the NSA.
Clapper did not directly confirm the program's existence but acknowledged that the Post and Guardian stories "refer to collection of communications pursuant to Section 702 of the Foreign Intelligence Surveillance Act."
That section of the law authorizes intelligence agencies to collect information on non-U.S. residents as part of efforts to gather foreign intelligence.
He said the program cannot be used to target anyone inside the United States or U.S. citizens anywhere in the world and includes "extensive procedures, specifically approved by the court, to ensure that only non-U.S. persons outside the U.S. are targeted, and that minimize the acquisition, retention and dissemination of incidentally acquired information about U.S. persons."
"Information collected under this program is among the most important and valuable foreign intelligence information we collect and is used to protect our nation from a wide variety of threats," Clapper said Thursday.
"The unauthorized disclosure of information about this important and entirely legal program is reprehensible and risks important protections for the security of Americans," he said.
While the Post initially reported that the companies "knowingly participate" in the program, it later updated the online version of its story to remove that contention.
In its stead, the newspaper described a classified report indicating that NSA analysts were allowed to send "content tasking instructions directly to equipment installed at company-controlled locations."
AT&T, Verizon and Comcast declined to comment on the report Friday. Time Warner said it was unfamiliar with PRISM.
Microsoft said Thursday that it doesn't participate in any national security data gathering program. Facebook and Google said they do not give government agencies direct access to their servers.
And Apple spokesman Steve Dowling said his company has never heard of the program.
While controversial to some, the programs also have plenty of backers. Obama noted that Congress has repeatedly endorsed the programs on a bipartisan basis.
Conservative Sen. Lindsey Graham, a Republican from South Carolina, and Sen. Dianne Feinstein, a California liberal, both believe the methods are necessary to prevent terrorism.
"Terrorists will come after us if they can," Feinstein said, "and the only thing that we have to deter this is good intelligence to understand that a plot has been hatched and to get there before they get to us."
Graham said that as a Verizon customer, "it doesn't bother me one bit for the National Security Agency to have my phone number."
Similar efforts have floated to the surface for years.
After the 2001 terrorist attacks, President George W. Bush's administration authorized the NSA to conduct wireless surveillance of international phone calls that included at least one person believed to be an al Qaeda-affiliated terrorist.
The program was later ruled unconstitutional.
Another Bush-era program, the "total information awareness" program, would have combined vast government databases into a data-mining effort to look for suspicious patterns revealing potential criminal or terrorist activity. It was official dropped amid intense outcry from civil libertarians.
Also, in 2003, a former AT&T technician made a splash when he alleged that the telecom was routing all Internet traffic into a special NSA-controlled room in San Francisco.
Last year, Bamford wrote in Wired magazine about a huge data center being built for the NSA in Utah. Officials have officially labeled the center as part of the nation's effort to fight cyberattacks, but the Wired article, citing former NSA officials and others, said it was part of a huge surveillance program that would take in and analyze untold amounts of data.
Obama takes heat
The reports have increased scrutiny of Obama's record on balancing citizens' right to privacy and the government's efforts to combat terrorism.
Days after taking office in 2009, Obama vowed, "Transparency and the rule of law will be the touchstones of this presidency." But on Thursday, the left-leaning Huffington Post on its home page conflated an image of Obama with one of his predecessor, Bush, in a move to criticize the secret surveillance both administrations have been accused of.
A New York Times editorial said "the administration has now lost all credibility" when it comes to overreaching in the name of fighting terrorism.
Obama said Friday that he entered office skeptical of the programs. But after thoroughly vetting them and adding additional safeguards -- which he did not identify -- Obama said he concluded they were worthwhile.
"My assessment and my team's assessment was that they help us prevent terrorist attacks," he said. "And the modest encroachments on privacy that are involved in getting phone numbers or duration without a name attached and without looking at content, that on net it was worth us doing."
Obama said he welcomed debate on the issue, but said some compromises are going to be necessary, no matter what.
"I think it is important to recognize that you can't have 100% security and then also have 100% privacy and zero inconvenience," he said. "You know, we are going to have to make some choices as a society."
CNN's Ben Brumfield, Greg Botehlo, Jason Hanna and Julianne Pepitone contributed to this report.