Smartphones with glass front and back tend to be exquisite devices that are well designed. They look and feel good in the hands. However, there is a downside to all that glass. With a glass front and back, note that no matter how you place your mobile down, it will be doing a lot of sliding, even on the slightest incline. More like moonwalking, as SojiTweets put it.
I can imagine that this must be how many iPhones got their broken displays: they slid off a table, stool or couch. Or not.
I have the Innjoo One 3G HD here with me. It has a glass back and it has been doing a lot of moonwalking. It has dropped to the floor from my favourite couch about five times in the last two weeks. Thankfully, nothing has been broken yet. I shall have to quickly adjust to this new reality and hopefully avert a breakage in the future.