Four and a half years after contractor Edward Snowden abruptly left the U.S. with a trove of highly classified secrets, the National Security Agency and its counterparts in the U.S. intelligence community continue to struggle under the crushing impact of his actions. Terrorists, spies and other NSA targets have retreated to the safety of encrypted apps and the deep web. While it's made progress, it will take years before NSA regains its edge. In the meantime, some very nasty things may happen because bad actors are able to hide almost completely. In this episode, NSA Deputy Director George Barnes says Snowden did much more than steal and leak highly classified documents, he opened a window into the NSA's thought process. Although the agency is rebounding very quickly, it's a difficult process.