Avraham Rabby, a retired US Foreign Service Officer, was physically removed from a Dragonair flight because he declined to take a window seat rather than an aisle seat. This is not your usual airplane seat dispute; according to Dragonair, blind passengers must sit in window seats.
Beneblog has an account of the incident, complete with photos: Dragonair Hauls Rami off the Plane
Dragonair’s seating policy, as outlined on the corporate website: Seat Allocation for Passengers with Disability
I tried to find the “safety requirements of the Hong Kong Civil Aviation Department” cited by the airline, but had no luck. If you find them, let me know.
More about Mr. Rabby, the first (only?) visually impaired FSO: A U.S. Diplomat With an Extraordinary Global View
Scott Rains at Rolling Rains provides an list of similar incidents: A Rocket Scientist Witnesses a Blind Man Being “Launched” from a Dragonair Flight
In her post Blinde sitzen am Fenster – oder sie fliegen raus, Christiane notes (in translation) that “The background of these regulations that some air carriers have is that they believe disabled passengers shouldn’t be allowed to be in the way of non-disabled passengers in case of an evacuation, which I find discriminatory, not to mention that blind passengers wouldn’t be sitting around, they’d be going with the flow and would find their way out in the dark faster!”

When I flew with AirAsia, I took the aisle seat after being carried into the plane and placed there. I was told to take the window seat because according to the safety officer my being on the aisle seat may impede the movement of the passengers in the same row in the event of an emergency evacuation. I argued but to no avail. It was the window seat or else…
As it was mentioned in Beneblog – it must depend on the airline. I’ve never been told to take the window seat and I’ve always taken aisle seats – even on budget airlines.