Technically, there was no iPhone 2. There's iPhone, then iPhone 3G, then 3GS. The latter 2 had a plastic back. And aluminum does break. It just doesn't shatter

Technically, there was no iPhone 2. There's iPhone, then iPhone 3G, then 3GS. The latter 2 had a plastic back. And aluminum does break. It just doesn't shatter like glass can.