They won't, for quite a while because it's good strategy. Don't let your opponent know they're trapped until the very end.
Had the government gone all-in trying to stop piracy, or drugs, back in the day they'd have kicked off this privacy awareness years ago, when they were much less ready. Now they've had a chance to gear up and get behind the terrorist attacks as they happen with stories about the chat clients they use, or how their iphones kept police from reading their texts, etc. With a little more of this by the time they do crack down not only will the tech be much more refined but there'll be a properly trained group of people who defend the censorship on safety, or moral, or whatever grounds, to keep the heat away from those who made the decisions.
