NSA whistleblowers J. Kirk Wiebe and Bill Binney have been sounding the alarm about government intrusion into Americans' privacy for years. They joined Megyn Kelly today to give us some revealing insights into how the agency works after President Obama defended the need to monitor Americans' phone calls.

Obama said today that nobody at NSA is listening to your phone calls, saying they are gathering "metadata" like the numbers involved in a call, how long it was, and where it was made from. But Wiebe said there is a common misconception going around about this aspect of the program.

"Aggregated metadata can be more revealing than content. It's very important to realize that when an entity collects information about you that includes locations, bank transactions, credit card transactions, travel plans, EZPass on and off tollways; all of that that can be time-lined. To track you day to day to the point where people can get insight into your intentions and what you're going to do next. It is difficult to get that from content unless you exploit every piece, and even then a lot of content is worthless," he explained.

Watch the full interview above!