Hitting is a bad thing. It causes a bad and imo somewhat hostile atmosphere between children and their parents. I am not at all for anti-authoritatian stuff. But hitting takes it too far. I also think one shouldn't shout at children, at least not if they are ~below the age of 12 (if they get older and do really bad stuff then yeah, they might have to be shouted at).
If you have to resort to violence, no matter how little it is, you show nothing but how pathetic and weak you really are. If your only way of dealing with a CHILD for

's sake is beating it that is downright sad.
You have to show a child his or her limits. You shouldn't and actually musn't let the child do what it wants. That would also be some kind of "crime". But it is very possible to talk to the child in a strict but calm tone if it does something wrong. Or if it has to be disciplined. I stand to it - every child, unless it has major psychological problems, can easily be disciplined by just normal words and actions such as cutting pocket money etc. It comes down to nobody but the parents to act in a correct way and it will work all fine. My parents never hit me and they never had big trouble with me either. If a parent doesn't manage to do this, it is a problem on his side 99% of the time. It is same with teachers - unless the class is really "different" the problem is on the teacher's end most of the time.
Yelling and shouting is almost as bad. If a >10 years old child makes you lose your temper and you end up shouting at you you are a pathetic parent and should think whether you are ready to have children at all.
Thank god beating your children is illegal nowadays. Letting someone who is MUCH stronger use physical violence towards a child is a horrible thing. If you cannot deal with your child without violence, then well you should rather give it away or talk to a doctor.
I know it isn't that easy to always be calm etc. But it is very well possible.