The thing that struck me in the story about the kid getting killed on the motorway was not any sense that it was his parents' fault, but the immediate knee-jerk reaction that "there ought to be signs up and a big fence" to stop anything like that happening again. As if motorways are some sort of hidden menace! It just struck a chord with the modern obsession with DANGERS and HAZARDS which means everything has to carry a WARNING, on the grounds that people are presumably too stupid to realise that crossing a motorway on foot might not be a great idea. Kids never pay any attention to signs anyway, if anything it's just going to make the danger more alluring. And it might seem like a tenuous link to connect this with the smacking thing, but I think it's all part of a very pernicious and damaging trend towards treating kids as uniquely vulnerable and precious (while at the same time bombarding them with manipulative advertising from the second they pop out) which is having consequences as far-reaching as the breakdown of discipline in schools to childhood (and subsequently adult) obesity.
So that's my two cents. If I gave anyone the impression that I was indiscriminately "pro-smacking" then I'm sorry, that's certainly not what I think, any more than saying you support the availability of abortion makes you indiscriminately "pro-abortion". I support the right of parents to bring their kids up as they see fit, within reason of course, hence my point about the huge difference between admonishing a child, which is a hopefully very small but nonetheless important part of upbringing, and physical abuse. If you've got kids going to school with big bruises, that's obviously completely unacceptable, and it's very important that we have social services and police with the powers to intervene in these cases - but at the same time, I think it's a very dangerous path to go down if we could end up with parents being charged with assault for administering a basically harmless smack to a child when all verbal reasoning has failed, which would likely end up in a situation whereby the child could be taken into care, with the very real possibility of lifelong harm being inflicted as a result.