We were in the shop a few days ago when a young mum literally exploded into the shop with her two kids, one about three and one about four. She went round the shop screaming and shouting at them "GET OVER HERE!" "MOVE!", treating them with such impatience and aggression. I tried to feel sorry for her, maybe she'd had a really bad day/had a horrible partner who'd wound her up/etc until the little boy did something to annoy her and she shouted in his face "YOU'RE AN ARSEHOLE!DON'T EVEN LOOK AT ME!"
Anyway we all just looked at the floor as she was so aggressive, I got the impression that if I'd even briefly made eye contact with her she'd have started a fight with me.
I felt so bad for her kids and wondered afterwards if there is every anything you can do in a situation like that. Could you say to the child "You know it's not OK for anyone to speak to you like that, if something that a grown up in your life is doing is upsetting you you can tell a teacher or another grown up you trust". Or would that make it worse? I honestly don't know.