In addition to taking down the sites of dozens of high-profile companies for hours (and, in some cases, days), Amazon's huge EC2 cloud services crash permanently destroyed some data. The data loss was apparently small relative to the total data stored, but anyone who runs a web site can immediately understand how terrifying a prospect any data loss is. (And a small loss on a percentage basis for Amazon, obviously, could be catastrophic for some companies). Amazon has yet to fully explain what happened when its mission-critical and supposedly bomb-proof systems crashed, but the explanation will be important. As will...