I remember being out with my wife, her sister and her sister's daughter and husband. We were walking down a fairly crowded street when this guy passed us, hitting the baby carriage quite hard to move it out of his way. My wife's brother-in-law made some comment I can't remember, but the guy who had hit the carriage turned around and started yelling and I was sure a fight was going to break out. This guy was in a rush and thought everyone should just get out of his way.
A friend of mine was the manager of a comic store and when kids would point to something, and say "I want that" or "give me that" he refused to serve them until they asked politely and said "please". This got him in trouble with a number of parents, but I supported him. People aren't teaching their kinds any kinds of manners anymore.