People who threaten their children in public.
"If you don't stop your whining, I'm gonna beat your ass" No you aren't. Please, if you actually disciplined your child, it wouldn't be acting like a brat right now. He knows it's an empty threat. He knows he's annoying everyone around you, and you will eventually give in to him to stop people from looking at you.
And I probably should add, people who don't have children (cause they're smart) who know they are the worlds experts on raising children. (Not that I am like that at all!!)
I got a bazillion more