Do you say something if you see someone harshly disciplining their kids?

I agree with you. I do not spank my child, although she is told it's a spanking. She gets her butt swatted when she's pretending she can't hear me or is screaming so loud that there's no yelling over her. I think it would depend on the situation whether I would interfere with another parent or not though. If they are hurting the child or it's obvious that the child is treated badly a lot, then I would either tell them to knock it off or I'd just call the cops. Then there'd be a record that the parent has abused the child before, and child protective services would be notified. Everyone flies off the handle sometimes, and that's okay, but you should never hurt your children.