Love the idea. If you wish to incorporate social stream data, check out http://socialsafe.net

I've used it to back up and then delete my personal FB account, and continue to archive instagram, linkedin, twitter, blogs, etc. etc.

What's more, even though their interface is kinda weird, they store all kinds of granular data in a very nice SQL database which contains more then they represent in their reports, and can be be repurposed in many different ways...