On the train I saw a man roughly handling his toddler, swearing at him and shoving him roughly to sit 'in the dirt' because his dirty shoes touched the mans bag and left mud on it. He was swearing and berating him along the lines of 'you ruin every fucking thing etc etc' He caught me looking and started shouting 'Now that woman is looking at me like I'm out of order' so I simply said 'yes I am looking at you, are you going to slam me on the floor and swear at me or do you only pick on babies' I was left shaking and the child's mother approached me to apologise and said he just gets stressed, I urged her to protect her child from the mans temper and she just shrugged. I just worry that if you behave like that in public what do you do in private? Should I have done more?