It is absurd that you are so concerned with this. First, if you are so concerned about people listening to your phone calls, maybe you should think about what you are saying. More importantly, when you are trying to find the money to pay your heating bill this winter, will this be very important? Criminals can access your phone calls and email with absolutely zero checks and balances. Get over it.
Against logic there is no armor like ignorance. - Dr. Lawrence J. Peter