Can you really by schoolgirls used underwear in Japan?

I've heared from quite a few people, that you can buy schoolgirls used underwear in vending machines, and it sells too. It is deffinitely apparent that japanese men, are slightly worshipping of schoolgirls. However, I don't really understand why this is wrong, as I think a lot of school girls are hot although I am only slightly older than school age. Anyway, who else has heared anything about this?