My daughter and SIL arrived at a small local airport only to find their flight home had been canceled. They had to get back for work so with the airline's help found another flight on a different airline and their tickets were switched for the new flight. They were nearly strip searched and had their luggage ripped apart because the ticket had been purchased the SAME DAY they were flying and though no cash exchanged hands, it was processed that way.
Of course this happened in 2003, but from what I'm reading here procedures have not changed that much. Same day purchase using cash, with or without luggage, still seems to send up a red flag. And I had not reported them three times to authorities as being extremists!