> Before this there was no way to literally monitor everyone The DDR did it Another important factor is that until 20-30 years ago people communicated a lot l

> Before this there was no way to literally monitor everyone The DDR did it Another important factor is that until 20-30 years ago people communicated a lot less They mostly talked face to face The challenge today is not easier: to literally monitor everyone is not possible, the signal to noise ratio is too high They could listen to everyone, it's doubtful it is possible to extract any meaningful information on random communications between random people that are not being monitored because they are already of interest As someone else said metadata is more important because it allows to create connections between actors from thin air. When you have narrowed the scope, listening becomes a lot more effective.