One of the major points made in the article is that nobody hears about the attacks that get prevented. It may just be that surveillance is very effective.
It's all very well to talk about the attacks that were quietly prevented. However, international terrorism is a well-studied problem, and there are several countries who have to deal with it, and they are trying a small variety of approaches. We don't have to speculate in a vacuum.
At least speaking of aviation security, we can pretty confidently say that the billions of dollars we have spent have, largely, accomplished nothing but political theater.
As an actual security expert who has studied this issue in depth concluded:
> Since 9/11, approximately three things have potentially improved airline security: reinforcing the cockpit doors, passengers realizing they have to fight back and -- possibly -- sky marshals. Everything else -- all the security measures that affect privacy -- is just security theater and a waste of effort.
I mean, look at the USA's terrorism laws. 99% of arrests from the TSA or the Patriot Act are related to things that had nothing to do with terrorism.
It's all just theater unless you can show that countries without that level of paranoia and invasiveness are getting attacked much more often. And I don't think that's the case.
Except for all the time the government spends trumpeting the attacks its has supposedly foiled (which mostly turn out to be comical, implausible plots, often instigated by government agents.)
The government would be shouting from the rooftops if they've prevented any attacks, if only to justify the surveillance. Pre-2015 there was a report that mass surveillance had not prevented a single attack. I'm not sure if that statistic is still true, but I imagine it is.
It does them no favors to keep the attacks prevented hush-hush, as it leads citizens to believe it isn't working at all.
Former NSA analyst, head of the spying program, calls it useless. [0] And more information/people-in-the-know [1].
[0] http://dailycaller.com/2013/06/10/what-do-they-know-about-yo...
[1] http://www.washingtonsblog.com/2013/07/the-fact-that-mass-su...
Remember the Boston bombings? I sure do. The FBI had a line up on them before the fact, then were too slow/stupid/whatever to prevent the bombs from going off. To repeat: they had information in hand as a result of surveillance, then still fumbled the ball.
At the core of these "security vs liberty" debates is usually three assumptions which are fallacies:
1. Complete security is possible, if only we give up our liberties (it isn't, look at violence in prison populations)
2. Complete security is desirable, so we should give up our liberties (it isn't, because we'd be in prison)
3. Giving up our liberties will have no unintended consequences (it does, involving willingness to put new ideas out)
For example, a common remark in discussions on relevant topics are paraphrases of that "those who would give up essential liberty" quote. Yet, those comments appear much less frequently of discussions of other sacrifices of liberty for the sake of security.