How rude is it to correct other people's children's behavior?

I’m talking about in public.

As I sit here waiting for Star Trek to start, I am pondering the very rude behavior of children these days. While I was waiting in line for popcorn some kid just walked about an inch in front of me to reach across the counter to get napkins. No excuse me or anything.

I bite my tongue during moments like this. It seems to me people are very lax about teaching manners to their children these days. I so want to correct these behaviors. I just want to say, “hey kid, can you please say excuse me next time?” Not to be rude, just to let it be known that such behaviors are inappropriate.

Now, I am a former crisis counselor and case manager, so I have this instinct to try to correct behavior. Is it wrong to just do it at the movies, for instance.

Do you bite your tongue? How rude would it be to address the child and/or parent about ill-manners?

My parents would never have abided such behavior in public.