No Fly's on me

At United Airlines check-in, the over-stressed agents herd everyone to the self-check kiosk ("Mr. Chicken") first, to reduce their workload. For some time now, I've never been able to get my own boarding passes, and been forced to line up again, at the trouble-makers' line. Inevitably, the check-in agent will try to key something in by several different ways, and then have to call someone, and read out my personal details somewhat loudly. I had always assumed that my transborder itineraries were the reason. Except two weeks ago, I got rejected on a US-US domestic flight.

Today, I asked for an explanation. It seems that my evil twin brother with the same name has got himself on a No Fly list....