It seems some Sony Xperia Z owners have had their 5-inch phones randomly quitting on them, forcing a hard reset to revive the bricked handsets, and apparently that doesn't always work either.
Sony's apparently got a fix for the bug incoming, even though there doesn't seem to be a known cause for the instant bricking. For what it's worth, our Chris' Xperia Z hasn't crapped out on him yet, but what about you guys? Anyone had their waterproof slab spontaneously turn into a brick? [Xperia Blog via Android Central]