It's interesting to read the "two sides" on this thread. As a white male it is easy for me to be on one side. In fact, sometimes only my being gay keeps me on the other side.
I have the tendency to agree with profiling--after all, as some have said, it has been a certain group which has caused recent events. But then as I came from the US into Canada (something I have done many times), I was singled out and my 2 carry-ons were gone through thoroughly and I was interrogated by customs, not immigration.
Why?
Well, I have a beard and dark hair. I have both a German and a US passport. I flew to Canada to start my RTW which was going to take me back into the US the next day. Mileage runs make little sense to poorly paid gov't employees. I had some Turkish Lira since pre-Tuesday I thought Istanbul may be fun to visit. Bad choice post-Tuesday--at least in some people's eyes.
I felt totally harrassed. MY country had been attacked.
I can only think that other Americans who are Moslem, have the WRONG names, look WRONG, etc. would/will feel similarly.