Each family and kid is different... some would be upset if the kid did that, others wouldn't , like you. I usually ask the kid what they are doing and why and if the kid is fairly reliable and explained it was old and nasty anyway, I would let him go ( I certainly wouldn't make ANYONE pick stuff out of the lunch trash!- EW!) I might mention it to the parent when I saw them though. If you ever saw the nice things that end up in lost and found and go to the shelters, you would be appalled though! Every 2 months they send 2 -3 contractor bags of clothes out of our small school's lost and found!