If "black Muslim" means a follower of Louis Farrakhan -- then it is quite a different matter than if he were simply black and Muslim, where his being Muslim is the neon sign flashing "Intern these enemies of the USA".
where his being Muslim is the neon sign flashing "Intern these enemies of the USA". Yes, true. I don't think anybody should be interned (yet - it may happen) but they should certainly be closely watched.
Farrakhan's group is dangerous, but personally, I think just about any mosque is dangerous. Converts (of any color) are frequently the most fanatical, too.