And it is not from human vandals. It is from large, furry vandals. The prime mission of every Yosemite bear is the liberation of the human's food as much and as frequently as possible. Traditional bear food takes a lot of effort and is not as much fun. Besides, humans expect it of us in Yosemite.
Many humans leave tasty goodies in parked cars all over the park, especially in Yosemite Valley.
Check out every car at the standard trailheads. Pay special attention to the small cars with the windows open a crack. They are easy to open by peeling down. Otherwise, smash the glass. Food hidden in big American cars inside the trunk is not worth the bother.