Chipping our kids backpacks

I found this article to be fairly interesting. I'm not sure something like this could catch on in the states, but getting a page or email when my kids enter and leave school is a fairly comforting idea. My children are 7 and 9. I'm not sure how this would infringe on their rights at 15 and 17. I think this is a good idea for younger children, but I think we need to extend our teenagers a bit more respect and trust. While the article doesn't mention the age groups of the children, it does imply that older kids are covered also. I think this is a technology we'll definitely have to watch in the future. I've seen a number of uses discussed for the RFID chips and they seem to be getting more and more imaginitive.