A folk artist from Vermont hand-screens t-shirts with the sl…

A folk artist from Vermont hand-screens t-shirts with the slogan “Eat More Kale.” Chick-fil-A, the fast-food chain, which has long used the slogan “Eat Mor Chikin” in its advertising , sent him a request to stop using their intellectual property. What is the basis of Chick-fil-A’s complaint?