Also, if you know arabic, you know the word for black and slave are the same. Razib's comment is apropos. It's also ironic that blacks in the past have been drawn to Islam even though some of the worst oppression and conquest came by the Arabs in ~50 years over North Africa, and they thought that somehow they were "going home." 
 
David, it's a nightmare due to Mo, or several of his biographers, including al tabari but equally with Ishaq, jalalyn, etc. Thankfully many still have their real humanity, but the leaders really stifle them in numerous, dangerous ways.