Our culture is becoming less and less polite as a result of everyone subscribing to different social rules if they have any at all. The rules are not there to "infringe" on your right to act like a douche, they are there to prevent misunderstanding and enhance communication, if you do any of the things listed below then you are wrong and/or simply ignorant of your own cultures (assuming your an American).
1. wear a hat indoors
2. talk on the cellphone at the dinner table
3. bring a sidearm to the dinner table
4. eat steak with a salad fork
5. fly a US flag upside down (unless of course your hoping a passing ship will see it and rescue you)
6. the list goes on and on............
.....and while it's not actually "wrong" I am also of the firm belief that anyone who puts "steak sauce" on steak should be shot and deserves neither steak nor sauce.