I still remember the exact words my father spoke right before the plane crashed into the world trade centre: allahu akbar !
Ok, let's break this down. Is this comment intended to convey the fact that your father was involved in the 9/11 attacks? Have you yourself been taught to believe in Islamic terrorism?
My friend talked about how Islamic terrorism is a real problem and I think it should be eradicated.
I can see that you were joking earlier about 9/11, which is something of a relief, but this is still a subject that is no laughing matter. The Islamic religion teaches followers to never kill or start wars, and it was only a radical splinter group who distorted their beliefs into justifications for terrorism. While terrorists should be stopped, we shouldn't imply that all Muslims either engage in, or even condone, terrorist attacks.
I can't expect a censors to hear the term Islamic terrorism without freaking out, but I think I'm going to be able to point out the irony.
Just know you may be judged very harshly if you make that type of joke.