I most certainly believe you, as this happened to me today!  I've had my phone about a month.  I have been extremely careful with it because of all of the glass it has.  It was sitting on my counter top while I was working on my newly tiled island and I heard the crack.  I thought I had broken a tile on the island, but there was nothing wrong with it so I thought nothing else about it until about an hour later when I picked up my phone and the back was completely shattered.  It looks just like the pictures you posted here!  I was completely taken aback by this!  Of course LG, the manufacturer, doesn't cover physical damage, regardless of how it happened and they want me to be without my phone for a month while they fix it and charge me to do so.  I contacted my insurance carrier and they said they can't prove whether I did it or not, so they would have to charge me the $150 deductible; however, I would have another phone before I had to send them the one I have.  This is crazy!  I get that neither they, nor I, can prove that it "just happened", but if I'm not the only one this has happened to, then they should be aware there is a problem.  They tell me they've never heard of this happening before.  I can honestly say, as much as I love this phone, I will never buy another with glass on the back of it.  Its a shame LG doesn't stand behind their product enough to replace it when they know this is happening.  You all can say this is BS or that I obviously did something to the phone, but I was here and I know for a fact that this happened without any physical contact whatsoever.  I wouldn't suggest purchasing this phone...just in case it might happen to you.