Bill Moyers spoke with investigative reporter Julia Angwin, author of the new book Dragnet Nation: A Quest for Privacy, Security and Freedom in a World of Relentless Surveillance. The full episode is above.

BILL MOYERS: What has happened to the Fourth Amendment? That's supposed to protect "the right of the people to be secure in their persons, houses, papers, and effects against unreasonable searches and seizures" such as you have just described?

JULIA ANGWIN: Right. Well, the thing is, the Fourth Amendment protects the actual physical walls of your home. And so in fact, the police still need a search warrant to knock on the door and come in. But the problem is, technology has reached into our homes in other ways and essentially there's an exception to the Fourth Amendment for that.

There's something called the Third Party Doctrine. Which is a Supreme Court precedent that basically says once you give your data to a third party, whether it's a bank, a telephone company, then you have lost your privacy interest in it. And so the police can get it there. Well, nowadays, our papers and effects that we used to store at home, we basically store outside the home at these digital places – Google, even our online banking. And so then there's a much lower standard for the government to get this information.