Tagging the child for the child's sake is a great idea. Tagging them for the parent's is not. I don't think you will find anyone that says we shouldn't do everything we can to make kids safer.
Maybe there should be a test that must be passed in order to have kids. I can see it now:
Question 1) The statement, "Boys have a penis, girls have a vagina" is true or false.
Question 2) When a baby cries, you should: A) Close the doors so you cannot hear him/her. B) Pick the child up and shake briskly until he/she stops crying. C) Tape a pacifier in the child's mouth so that he/she can no longer cry. D) Check the child's diaper, feed the child, or hold the child.
Question 3) You should expect to spend about how much time with your child? A) Five minutes a day B) Ten minutes a day C) Thirty minutes a day D) More than thirty minutes a day.
Insert your remaining questions so I don't go on forever.....
If this test is failed the parents to be would then immediately be steralized.