I think the so called unruly passengers were not aware that this is not an Indian Airliner. Such sites are common if u are flying any Indian Airliner. And when the cabin crew tries to bring some sense into them they threaten stating contacts. And they are generally able to get away with such behaviour.
It has been observed while I was travelling by international flights. Especially Indians are not following the instructions by the authorities. Its disgusting to see after the warnig also they keep on talking on the phone, Not fastening the seat belt, or running towards the lavatory while take off etc. One must be abide the rules and regulations which is purely for our safety. But it is a bad name for Indians. Indians should start behaving well.
