Its law or Not, One Should Never Spank a Child
Children must be treated very fairely and No one should every use spanking or any kind of physical abuse to discipline them.
Children doesn't understand what they are doing is wrong or right and hence are not guilty.
But at the same time, Laws should not be restrictive and harsh. Sometime law itself rule against the welfare of a child.
I know one of the case, my friend mentioned to happened in New York with an Indian couple, where a kid got burn with hot iron. Her mom used some herbal ointment and he was all good. A year later, her teacher noticed it, and reported it to police and father was iventually had to go to jain for not taking the child to doctor !!
But as a general rule, we should try to avoid getting into such a trouble.