I can tell you there are a LOT of foreign-born Pakistanis and Arabs in airline aircraft maintenance organizations and working for contractors.
I remember reading this at the time, but I've heard nothing else since. Are they investigating this? I also rmember reading that a number of middle eastern men were sitting in the jump seats in the cockpits (as courtesy passengers) of flights that were grounded, or never got away from the gate that day. What happened to those guys? Were they apprehended and cleared?