This is possibly the exact reaction the perpetrators wanted. Muslims/Arabs, anyone who looks remotely 'non-European' to be persecuted to get them firmly on one side of the fence or the other.
A part of the bigger picture than last Tuesday? The planning wasn't just to prang a couple of cabs into the WTC on the whim of 'Anti America/Capitalism' me thinks!
The reaction of the American people and the world following the event was carefully thought out. I even subconsciously give the above groups a second look (why?), do you now? I think events will unfold.