Now we turn to a huge argument tonight about privacy and safety in america. We've learned that the obama administration quietly accessed the phone records of millions and millions of americans. Saying... See More
Now we turn to a huge argument tonight about privacy and safety in america. We've learned that the obama administration quietly accessed the phone records of millions and millions of americans. Saying it was necessary to guard against terror attacks. Abc's chief investigative correspondent, brian ross, is here to break down whether your phone records were among those handed over. What was so surprising, even to some former top counterterror officials was the scale and the scope of the collection program. Something both the bush and the obama administrations have tried their best to obscure. Reporter: No american is exempt from the secret program. From office workers in new york city, to members of congress, hollywood celebrities, teenagers in the mall. The government doesn't listen to the phone calls, but it obtains the records of every call made, to what number, for how long and from where. All to the outrage today of privacy advocates concerned about potential abuse of the data. It reflects what you eat, what you read, your political affiliations, maybe your faith and mental health. Reporter: The program began under president bush who assured us that it was limited in scope. We're not mining or trolling through personal lives of millions of innocent americans. Reporter: But the publication by a british newspaper of this top secret court order, requiring a verizon subsidiary to turn over all call detail records, including local calls, for its customers, confirms in black and white that the program continues and is all encompassing, not what congress heard from the obama administration's top intelligence official three months ago. Does the nsa collect data on millions or hundreds of millions of americans? No, sir. Reporter: And officials have told abc news it's more than just verizon, that there are similar secret orders for the records of all u.S. Phone companies. It is sweeping. It is not what I would expect out of the united states. Reporter: Federal officials call it a critical tool, used, for example, to track a spider web of connections for suspects like the accused boston bombers. I can tell you, to that end, within the last few years, there was a domestic case that was thwarted because of their ability to do this. Even so, officials we asked across the government today could not or would not provide any specific details of any thwarted terror plot connected to the secret phone records. And like the program itself, too secret are if the public to know. And we've been talking about whether it was just phone records or more. As abc news has reported over the years, internet records have been obtained and they tapped into internet lines to get feeds of what's going across the internet.
This transcript has been automatically generated and may not be 100% accurate.