Standard MO for cowards.
You can tell who the craven are. They form gangs...
No audio on that video, but I clearly hear the wonderful sounds of the sub Sahara. You could see the tension building as they sauntered around the platform eying their prey. It was like watching a scene from mutual of Omaha's wild kingdom. And those officers arriving on the scene were top notch seeking out the trouble makers. Letting that train go was the right thing to do. :-P
This is what happens when an entire generation of teenagers grow up without Fathers.
AGA. Always go armed.