Jim,

While I do agree with your position on fear, I think your position in this particular case is not quite right on. This was not the result of one person's fear and their passing a note to a crew member, it started with that action. Then certain people refused to sit in their assigned seats. These people refused to follow the instructions of the crew and of the captain. IMHO, once they chose to break the rules (not sit where they were assigned) and to disobey the crew instructions (Please move to your assigned seats) it was a good decision on the captain's part to have them removed from the plane.

I have no information regarding how that group of people acted on whatever other flight they mayy have boarded subsequently.

I don't know about other countries but in the US it is a federal felony crime to disobey the instructions of the flight crew.