The U.S. government last year discovered that it was the victim of the largest-ever cybersecurity breach in its history, in which Russian hackers allegedly used a software exploit to access a deep trove of sensitive information. It was the latest escalation in a digital battle that is only expected to escalate, via a global black market where governments can buy everything from ways to hack laptop cameras to power grids.

Dan goes deeper with Nicole Perlroth, a New York Times cybersecurity reporter who just published a book titled "This Is How They Tell Me The World Ends."