not sure if this has been said yet...
But my worry with being legally allowed to smack is that although most of you will know that a smack is not meant to really hurt, there are an incredible number of parents out there that simply don't know what is acceptable.
I have seen them myself in the supermarket and it makes my blood run cold;
an inquisitive toddler -being a toddler- reaches out and picks something off the shelf and the mother lashes out an attack on the child because she is fed up with putting the items back;
or in the queue for the bank and I hear behind me 'if you ask me one more time you will get a smack'
In public they feel that that is acceptable so it makes me worry about those children when behind closed doors.
I personally don't smack my children as I am fortunate enough to have never needed to. It makes it dificult for me to understand in that case why anyone would feel that they need to. I am no parenting expert and I have certainly been wound up to oblivion by my kids before but I have managed for 7 years to not need to smack and that pleases me.
Sorry if that last bit sounded a bit off- I'm not judgeing anyone here, I just wanted to say my bit.