Do we really need this movie ?

Rating: Null/10 (1 November 2013)

Do we really need a movie like this one to finally find out that slavery is brutal ?
Like we need a movie showing the sun rising in the East to realize that the sun rises in the East ?
OF COURSE slavery IS brutal, cruel, inhuman. Of course it HAS raping, beating, torturing, yelling, as well as angering, crying, weeping, begging for mercy.
Acting is good ? Nothing else is easier than pretending to be cruel, angry.
Not that I can't stomach scenes depicting cruelty, but I found the cruelty in this movie redundant.