I am afraid I have to disagree with letter writer Louis Netemeyer about the background checks on parents who want to chaperone children on field trips, school functions, etc.
It doesn't hurt to know exactly who will be in charge of your children when they are away from school property. In this day and age of nuts that we seemingly have everywhere, it never hurts to be extra careful.
I was a teacher's aide for four years and I had to have a background check, fingerprints, drug test and three letters of recommendation before the school district would hire me. I did not resent this in any way. After all, you are working with God's greatest gift (the children) and I know I would feel better knowing they are in trusted hands.