I don't think it will be possible to achieve total privacy. Simply because the Governments won't allow it. In this day and age, sadly, it is a fact that allowing total privacy in any form of communication is a very dangerous thing. The more complete privacy protection becomes, the more the people who have the most to hide will use it. We can certainly improve things like reducing targeted advertising and spam email but achieving total privacy? I don't think it will be possible or even desirable.