How would you punish this fellow?

Asking this question with a tip of the hat to jbfletcherfan who brought it to my attention, I wonder what you might see as an appropriate punishment for this guy? Is there ever any excuse for hitting someone else’s child? Where was the parent when a stranger put his hands on her baby? I’m pretty sure the mama bear in me would have come out and dude would have lost a finger – at the very least.