In a way, I think the traditional mode of representative government is part of the problem. It simply doesn't reward anyone to level with the public like that. I'd like to be shown wrong, can anyone provide a counterexample of a politician serving in office who persuaded the public to just accept it? The only sort-of example I can think of is US politicians who throw up their hands over teh gun control issue after a massacre and say they can't really do anything and then wait for the issue to fall off the front page. But that's also why so many people are disgusted by politics.
If you want politicians to stop engaging in security theater and the like, it looks like you're going to have to buy them off. With enough money a politician will apparently say anything. Doesn't sound too sustainable to me though.
They are trying to prevent terrorism. And they are sifting through lots of data.
They are also doing a lot of other things. I certainly hope terrorism isn't their main concern. Maybe some of that data is helpful preventing the odd hate crime. But it might just also be used for union busting or something like it in the name of stability and law and order.
Total surveillance is useful to control a population - but I don't think it's particularly useful as a counter terrorism tool.