The Burger King franchisee in New Zealand has been forced to drop a social media advertisement depicting westerners using oversize chopsticks to eat a new Vietnamese-themed burger offered by the fast-food chain. The controversial ad sparked online debate over whether the scene should be considered racist, after an ethnic Korean New Zealander mentioned it in a Twitter post that quickly gained more than 2.9 million views. The Burger King ad was later taken down. Some social media users…