The Snowden case has taught us a lesson, that is we should not trust anyone, let it be Microsoft, Google, Amazon, or any other public domain to host your own data or to transact “conversation” through email, Whatsapp-like chat room or Skype-like communication channel.
You should have your own data in your own possession, at your own office or other secured location that you can trust.
As for our users, they have their own software program installed at their own server, data at their own location, security controlled at their own hand.
Now, we even offer our users their own “Whatsapp-like” communication channel for internal and external use.