Outraged Parent-Rule to be a Decent Parent

How do you not pick up your child on time? I do not understand how that can happen. If your child is away or at a party don't you establish a pick up time and be there 10 minutes early? Especially today when we have cell phones we can reach our children/teenagers and work out a plan. It is not the responsibility of the world to get your child home. I have seen teens not have anyone there and not only does it break my heart I worry that they will never get home. As much as I believe that it takes a village to raise a child please be responsible for your own first!