蒸気船ウィリー
The first commercial success of Mickey Mouse came with "Steamboat Willie", released in 1928. In part, it parodied the silent film "Steamboat Bill, Jr.", released earlier that year by Buster Keaton. Under current US law, "Steamboat Willie" might be challenged for copyright violation as a "derivative work" of "Steamboat Bill, Jr." However, under copyright laws in 1928, this type of cultural production was unproblematic. This change has had a chilling effect on creativity, serving to reduce competition to the established media companies, as suggested by the subtitle to the original hardback edition of "Free Culture".