PBS News Weekend 
Season 8, Episode 89 of 99
Every year since 2010, the world's largest live-fire cyber defense exercise, called Locked Shields has taken place in Estonia, a country known for its technical prowess. This year, more than 1,000 experts from 30 nations, including the United States, took part in the exercise, which was organized by the NATO Cooperative Cyber Defense Center of Excellence. Each team from participating countries is challenged with overcoming a massive cyber attack from a fictional nation seeking to dominate the region. Critical infrastructure, banking systems, ports and air traffic control systems are among the targets. And while the scenario is not real, the attacks are meant to mimic real threats that NATO faces from hostile countries, including Russia. NewsHour Weekend Special Correspondent Christopher Livesay reports.
