I almost forgot to link to a study from a think tank in the U.S.:
"Do NSA's Bulk Surveillance Programs Stop Terrorists?"
Peter Bergen, David Sterman, Emily Schneider, and Bailey Cahall
New America Foundation, January 2014
This shouldn't be surprising. It happens quite a lot that superficial approaches are being preferred over boring, hard work. A typical reaction to crime hot spots is to patrol a lot -and visibly- with uniformed police in the area.
Meanwhile, what really helps is simply more resources for criminal investigations and prosecution in the judiciary system instead of a superficial show of strength.
What's different with the intelligence services is that intelligence services have only the spectacular, superficial and ultimately quite useless methods on offer. Police leadership has both the superficial and the actually effective approaches on offer and tends to advocate the effective ones, but intelligence services have nothing really effective on offer, and end up promoting their ineffective approach out of bureaucratic self-interest.
People who don't research diligently fall for the claims of the supposed counterterrorism experts and agree to funding their work - and then get largely blocked from observing if their money is well-spent by secrecy efforts (and depend on whistleblowers to learn on what methods their money is spent on at all).