It is unacceptable to yell at people.
While walking through the supermarket, someone almost runs into Kathy's daughter.
Kathy wants to scold the person who almost hit her daughter.
Kathy pulls the person aside and points out what the person almost did.
Kathy instantly raises her voice and screams at the person to watch where she's going.
The person is a bit ashamed and apologizes, and promises to be more attentive.
The other person looks at her like she's a lunatic and simply walks off.