You would have to look at the history of both blacks and people from the middle east to answer your question. as far as i know, they have been little to no violence commited by blacks trying to promote their way of life, religion etc. , and none that i know of that were targeting the overall public, as well as none using airplanes as weapons, or hijacking them. Now people from the middle east on the other hand...
and thats why i'm a bit concerned.