Two incidents. 1. In St.Louis airport, when i was taking a flight to India, they pulled ONLY ME aside. Took me to a covered area and did a pat down. And also they were checking my belt to see if there were any bombs.
2. In swiss Zurich airport. I was the only one who was asked to take my shoes off in the security check.
Now the above two may seem insignificant but it greatly affects your morale and make you feel humiliated when you are the ONLY ONE out of a queue of hundred people taken out to check.