Response #24 in a discussion on FlyerTalk:
My 10-y.o. son, like many kids, believes that backpacks have to be overloaded to work.
Recently, at LAX T-6 (shoe carnival central), the TSA removed 2 partially full water bottles from his backpack after x-ray screening.
On the return flight, at JFK T-9, they found 2 more, both of which had been in there all along and been missed at LAX. As we rode the escalator down in T9, I told him that if this happened again, he would never get upgraded until he was 21 (it’s a harsh threat…) — and he reached in to his backpack and took out another partially empty water bottle.