What would be the reaction of politicians if their every phone call, email, message were able to be read and published?
On the other hand, do you really want the neighbor's meth-head boyfriend to have NSA style access to your records? to your children's records?
Seriously guys, a world with zero privacy may sound kind of cool... in theory. But you have to realize that there are actors much more nefarious than most governments on Earth, and the impact to the lives of those who become "persons of interest" for that kind of actors happen to be more immediate and unpleasant.
But as for what this would be like, most likely it would be a society like the Borg (TNG Borg, pre-queen, not VOY Borg).
The political game is obviously rigged against us. Our strength is the technical solution, not the political solution.
The USA Constitution makes it completely clear: "The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized." This became a political problem for the powerful, so they concocted a legal notion amounting to the suffix "unless the search is imposed on everyone without particular cause" which has proven surprisingly effective and acceptable to the general public.
When all branches of government conspire to ignore the rules, more rules won't stop them.
Of course, most adversaries of the US aren't competent. Planning to jihad something? A good first step to not getting caught would be to never visit a jihadi website in the first place.