When paternalism becomes suffocation

Where to draw the line between paternalism and coercion? The word paternalism always connotes something positive even if a little highhanded, like a father taking out the rod to whack a child. Still it is seen as acceptable as long as it does not borders on cruelty, no tearing of flesh or blood dripping everywhere. Thus people happily used the cover of paternalism to commit crimes against their children, and even get away with it. To be paternalistic sounded so good, so righteous and so good hearted. When does paternalism ends and evil or wickedness takes over? When can a parent be sued for cruelty for stuffing a child with too much food? Or when does paternalism becomes over protective and takes the form of forced imprisonment of a child in a house? When can a parent be seen as robbing his children of their money by keeping it against their will and decide when and how much to return to them at his own mercy? Is there a limit to paternalism before it is called something else?