Not sure what your point is.
Is it that members of extremist groups signing up to drive school buses is nothing to worry about?
Or that it is something to worry about, but the FBI just swept it aside with "don't worry about it?"
I'd like to see the full alert text. This sounds pretty damn vague to me. What "foreigners" and "extremist groups" are they really talking about? Nothing in this says "Middle East" at all, if you'll notice.
I also saw nothing on this on the FBI site.