Цитата от Flavour :
Historical background and political settings:

Around the year 1960 the peaceful movements around Martin Luther King and other movements were opposed by the whites, who in general treated African-Americans like pieces of dirt, and by the Black Muslims. This movement was lead by "The Messenger of Allah" Elijah Muhammad and was in contrast to the peaceful movements radical and racistic (The white man is the devil). The members of this movement denied their surnames, given to them by the white slavemasters centuries ago.
Instead of their names they put a X as their surname, standing as a symbol for their lost African names.