FBI agents can’t point to any major terrorism cases they’ve cracked thanks to the key snooping powers in the Patriot Act, the Justice Department’s inspector general said in a report Thursday (...)
Nor can BND or BKA, apparently. Previous lists of allegedly mass surveillance-supported CT successes were destroyed even in cursory reviews by investigative journalists.
Authoritarian-minded people only presume that this kind of stuff* works. Just as they simply presumed torture would work. Or they watched too much TV and are much too manipulable.
Either way, the evidence still overwhelmingly points at all the mass surveillance having negligible utility, meanwhile it's obvious that it's cutting away a big chunk of civil liberty.
*: A.k.a. "Stasi-, KGB- and Gestapo-like interest in snooping and torture".