We currently have no legal system that can operate in a world without privacy. Maybe in a future someone could invent one, but current judge, jury, lawyer and prosecutor system require that each role has sufficient amount of privacy to be functional.

Imagine being in a trial against Google, knowing that they have access to information for all the participants and their family and friends. Internet searches, phone calls, purchases, browser history, location data, voice recordings, and all the analytic tools to analyze and extrapolate what details can be used for manipulation and sell an argument. How could such trial ever been conducted in a fair way?