This afternoon when I picked Ben up from school, he went to the toilet in the park before we walked home. As he ran back over to me, one of the kids from his school deliberately tripped him and he landed flat on his face on the grass. On the plus side, Ben falls down a lot, so he is pretty good at minimising the damage when he falls. I walked straight over to him, and the kid walked off with the other boys he was playing with.
I don't know what the appropriate response is from me. If I had been within earshot as it happened, I'd have said something, but I would have to have pursued him across the park to speak to him, so I glared at him instead, and made sure I knew who it was.
To me there is a qualitative difference between calling out a kid as they do something and chasing them across a park to reprimand them. At the same time, I feel like I have been complicit in nasty behaviour because I didn't speak to him. And then there is the problems I create for my child by being an overly interfering mother if I step too far over the line.
When do you intervene and speak to other people's kids? I suspect this is a theme everyone who has kids old enough has had to deal with.