Here's another.
I got into a DC-metro cab in June 2001, driven by a mid-50ish Arabic guy.
He refused to get out to put my luggage in the trunk, explaining that he didn't want anyone to see that he was driving a cab. (Huh? OK.)
And then for the next 5 to 10 minutes he oddly kept exclaiming that the highrise building I'd just exited was "a very strong building, yes, very strong." It was a bizarre non sequiter, I couldn't understand why this was of interest to him or anyone else. Not your normal cabbie conversation. Yet he kept talking about this "strong building" until I finally changed the subject.
He did mention that he lived in Herndon, which was where all of the Islamic charity fronts were closed down after 9/11.
When I recalled this incident sometime after 9/11 - months really - it gave me the chills. Did he know something?