The site says "you should own your own identity and content." Well, that's great in theory, but where should I put my identity and content? Should I store it on a flash drive? That seems a bit risky. Should I have a bunch of flash drives in security deposit boxes? That seems like a huge pain in the ass. How about a site where I can upload all of it! Well, now we're back to the same problem - but instead of it being on many sites, it's just on one.

I think the real answer is decentralization. Maintaining your data in many different places on the web and trusting that it's very unlikely that all of these sites will go down. Security and privacy, of course, is an entirely different matter.