The question is not a new one even in the brief history of cinema , which includes people like D. W. Griffith , the visionary feature director whose work fed racist stereotypes ; Leni Riefenstahl , whose ground-breaking talent served Nazi Germany ; or Roman Polanski , who in 1977 pleaded guilty to having sex with a minor and then fled the country , which did not prevent him from winning the Oscar for best director in 2003 for '' The Pianist . ''