Sounds interesting, I'll check it out.

> My call history is with my telco, my location history is with Google (and probably many others), my conversations are spread out among so many different apps. What happens when I want to query the data about me though?

That's a real problem right now. I asked that question in almost the same terms many times when I worked for Urbit [0]. I no longer work for them, but they still seem to have the best long term solution to giving you access to all your own data (specifically by putting that data on your own server to begin with).

[0] http://urbit.org