2) Some people don't trust their private data to 'the cloud.'
Yet you'll put the data on the cloud via this appliance and just require a username & password to it?
In addition to pyre's reasons, part of the point is to let people control their hardware, and to have better physical control of their data before it leaves the premises, e.g. encrypting email, as forgotusername suggested.
Comments
Why would the server have to be at home? Why would it not be enough for everyone to have e.g. their own EC2 microinstance?
No reason that it needs to be at home, but:
1) Ease of setup for the non-tech literate. Someone could buy it, plug it in, and have it running with minimal fuss.
2) Some people don't trust their private data to 'the cloud.'
2) Some people don't trust their private data to 'the cloud.' Yet you'll put the data on the cloud via this appliance and just require a username & password to it?
No, ideally you'll send it directly to other people's appliances, and use public-key encryption where possible.
It seems one could use ssh keys similar to what Amazon does with AWS.
In addition to pyre's reasons, part of the point is to let people control their hardware, and to have better physical control of their data before it leaves the premises, e.g. encrypting email, as forgotusername suggested.