I hear it started because some kid choked and died. Who eats the egg whole, I mean seriously?
I've never heard of any kid actually dying like that. I've heard of watchgroups THEORIZING that a kid could die, but I haven't actually seen any stories that I remember.
I agree it is a stupid law that violates personal freedom, but wiki cites 7 deaths worldwide from kinder egg choking :
Since 1991, at least 7 children worldwide have died of choking after swallowing the toy inside the Kinder egg.[7]
http://www.thefreelibrary.com/Mother+calls+for+ban+after+girl+chokes+on+Kinder+egg.-a060703736