While I believe that some forms of "lunch shaming" (I.e. Doing chores) are too much, I don't believe that children who's lunch balances are off should just be able to eat lunch. If a parent decides just not to pay for lunch the entire year, they would know their child is still eating the same lunch they would get if they were paying. What would keep parents paying for that students lunch? If they decide not to pay the outstanding fee, no matter how much, the school district has to eat that negative and it would ultimately hurt the school's budget in the long run. On top of this, a lot of times students, even in 12th grade, can't really be trusted to bring letters home to their parents and some parents might not check school mail. Having a wristband or hand stamp isn't necessarily shaming the child but it's a way the school can make sure the parents get the memo that they are behind.