Yup, Saudi Arabia will long be a source of grief for the world.
I want to say that observations like the OP's thread title are actually nothing to make fun of. It's a legitimate thing to be concerned about. But then the next question (before denigrating refugees) is what will the output of our various countries' vetting process be? Is the fact that the refugee demographics 'scary' a reason to want to ignore/mistrust/abuse/driveout the refugees that are actually approved?
There's no doubt some militants will slip through (it's a numbers game). And there's no doubt some refugees will radicalize later (and the bureaucrats will get the blame here, too). But nearly every refugee who makes in through the filter is going to be our ally in making a better world.