Kinda like how the Boston tea party did by dressing up as natives except without the racism.
Since you brought up racism: The point is to keep the cops from identifying you with facial rec, so doesn't it make sense for a white person to wear a mask of a black person, and vice versa? Or is it bad to fool the cops into blaming a black person for a white person's crimes? What if the mask is of a black celebrity? Nobody would believe that it was really that celebrity anyway.
Or maybe a white person should just wear a white person mask.