that is the situation in normal fare, hidden city ticketing would work. let's say at KE check in in USA, they hand u a letter saying that they expect you to take your flight to RGN, failure to do so would require a charge of fare difference, what would u do?

in most circumstance, it would. ot happen, but in this case, KE is stuck with all these tickets that they cant cancel, if they can scare some people for not flying. they win.