Disney is making a live-action version of Mulan, and with any live-action remake of a classic animated film, the casting is a major concern for fans. The difference with Mulan, though, is that it’s based on an epic Chinese poem that dates back to around the year 600 A.D. So, the story of Fa Mu Lan is not a Hollywood creation, but is instead a cultural touchstone for the Chinese. And a lot of people are worried that Hollywood, which has, in the past (and present) shown fairly obvious apathy toward promoting cultural representation, will continue its trend of whitewashing by casting someone like, say, Anne Hathaway in the role of Mulan. At least 20,000 have signed a petition against this possibility.
As The Guardian points out, this is a preemptive petition, as no casting decisions have yet been made for the film, which is still in pre-production. The petition has probably seen some added success because of the recent backlash to Scarlett Johansson being cast in the upcoming live-action adaptation of the classic anime Ghost In The Shell, a move that spawned its own petition that now has more than 40,000 signatures.
From the petition site:
For the audience, whitewashing implies that persons of color cannot be heroes (although they may at times be villains or supporting characters), leaving it far more difficult for countless children around the world to see themselves in the stories they love and think that they, too, can make a difference.