How do you picture the data cloud we hear somuch about? Perhaps in your mind's eye it is a universal, untouchablecollection of pixels and electricity pulsing somewhere far above our heads.Last night's Thinking Aloud featured a guest who is trying to change how wethink about the data cloud. In his book "The Prehistory of theCloud," he deals with the idea of privacy, the balance of human power inthe realm of technology, and the cloud as a metaphor for a tangible storagespace for digitized information.