take a look at "Earthweb" as a possible long-term approach

the book Earthweb (available free, without DRM from the publisher at http://www.baenebooks.com/p-833-earthweb.aspx ) shows an interesting future with a pretty logical extrapolation of the current trends in online identity and privacy. Even if you don't like the entire book, it's worth reading the first few chapters as food for thought about how it may be possible to deal with bigdata and similar threats.