Or they'd select the option saying "use local storage" instead of the one saying "use encrypted distributed storage", and then there's no worry.
The point of this is, there doesn't need to be one way.
Facebook (and G+ and everyone) enforce their fixed way onto people, and people have no choice but to put up with it (or not use the service, and thus not be able to communicate with people across the globe).
Doing it right means providing people with the ability to have things their own way - and that includes whether you store your photos on your home machine, or on an encrypted peer-to-peer network, or on your ISP's space, or on your flickr account, or on a dedicated server, or on a cloud data store, or on a corporate VPN, or wherever the photo sharer chooses.
Computers are supposed to fit around human's needs; so people choose what they want to do, and it's the software's job to do that as seamlessly as possible.
And
that doesn't need any one entity to spend lots of money on flashy hardware.
EDITED: 14 Oct 2011 21:09 by BOUGHTONP