South Korean police have raided Starbucks's national headquarters over defamation claims surrounding a controversial marketing campaign. The company launched a coffee tumbler promotion in May called "Tank Day" on the anniversary of the 1980 Gwangju Uprising, where hundreds were believed to have been killed by military forces, leading to a mass boycott movement. Tap the link in @BBCNews's bio to read more on this story. #Starbucks #BBCNews