There’s actually a thin plastic membrane on the inside of most cans. It helps preserve the taste of the product. There’s a couple cool chemistry videos on YouTube where they use acids to dissolve the metal without damaging the plastic, leaving a weird bag of soda with a can lid.
I have two absolutely gorgeous Nanos with zero battery bulge and not a single device that can run iTunes. I even have the 30 pin cable. Once upon a time I would’ve used the family PC but that thing has more viruses than the hospital thanks to my little sister.