Russian bots post-Parkland, Iran and Saudi Arabia square off and KFC runs out of C

After the shooting in Parkland, Florida, Russian internet bots almost immediately began stoking both pro-gun and anti-gun fervor. Plus, we speak with Frontline producer Martin Smith about his latest film, which looks at the conflict between Iran and Saudi Arabia. And bad news for fried chicken lovers in the UK — KFC is out of chicken.