I've written elsewhere that metaphors are not arguments, and a more general expression of that idea is "Metaphors are useful only for explaining, never deciding." (Perhaps On Deciding... Better should do a bit on what I call the 'metaphor' fallacy. I'm tempted to do so myself, it just wouldn't be as good. Too many people thinking about Internet issues resort to metaphors, which unfortunately is a form of intellectual laziness in this environment where so much is new.)