Wow, thanks for jumping in so early---this is exciting! Before I respond to your excellent point, I have to come clean here and say I just tidied up the topic a bit given my proclivity for typos and the like.
I think this idea of the cloud as anytime and anywhere to any device storage is right on. The interesting point you may is the where, what or how is not all that relevant to you. You just need to know that it is backed up somewhere else---but that in many ways is the limit of the cloud metaphor, you have no real conceptual idea of how anything is working. What's more, it starts to become this broader, nebulous sense of cultural anxiety where we begin to invoke as a kind of technological apparatus working against us. A terrible, but telling, example is a Hollywood film that came out in the fall of 2014 called Sex Tape. The premise is simple, and I'll quote Wikipedia here:
Jay and Annie Hargrove are a married couple, which, after having two kids, have sex at every opportunity. After Jay struggles to get an erection, Annie suggests making a sex tape. They film themselves having sex in every position listed in The Joy of Sex. When done, Annie asks Jay to delete the recording, but he ends up instead inadvertently synchronizing the video to several iPads the couple had given away over time. After failing to get it out of the cloud, they set out to get back all of the gifted iPads, leading to a series of awkward encounters and close calls.
While a pretty obvious example of the limits of Hollywood's imagination, it's interesting how the cloud here becomes an over-sexed white, middle class American family's worst nightmare. The cloud has taken revenge, through the various cloud-connected mobile devices we use regularly, and they ultimately find themselves trying to destroy the data center with the web servers where the videos have been sent to prevent this tape from going viral. The movie's entire plot depends upon two things: 1) the viewers shared anxiety that something like this could happen to them, and 2) a certain technical ignorance about what's actually happening and how it can be solved. In the end, the couple tries to destroy the web servers only to be caught and told they could have just sent an email to have the video removed. Again, the cruz of the film being no one understands the cloud:
I know this is a long-winded response, but what struck me about this film's response to the cloud in popular culture is the way in which the actual metaphor seems to support a willed sense of ignorance as to what's happening with our data, a reality that is equally scary given that far worse that some imagined Sex tape would be the fact that through these cloud based services we are being tracked and our data mined and sold. I think back to an olde metaphor popularize in the early days of the web: the information super highway. That figure gave you an idea of how things moved, and in some ways it remains far more useful as a figure than the cloud.