As a born and raised city dweller, I understand how frustrating it is to be sitting on the train trying to get to the intended destination and then someone gets on and holds the doors for a person who isn't even close. It's annoying but it's not serious enough to get violent...well, not for me. But in the following video, peep how this woman gets fire kicked out of her for holding the train door open:
Man, I have fast reflexes. I would have been back on that train whooping that azz in seconds!