@Ionus,
The feds seem to do a pretty good job getting information from organized crime groups (mafia and other criminal gangs) through professional (not medieval) interrogation techniques; also from other methods consistent with the U.S.Constitution. This despite the viciousness and secrecy of these organizations and some of their members.
Local police seem to get a lot of Information from and/or about a lot of equally vicious but not so organized criminals these days, even after reading suspects their Miranda rights, and without electrodes and waterboards and all the other little toys that are associated with high levels of "cooperation" but low levels of accuracy and reliability.
I think that if the job of intelligence gathering was carried out by trained and experienced law enforcement investigators used to dealing with violent, secretive criminal gangs, using finely honed professional skills, instead of by easily frustrated amateurs whose idea of effective interrogation and intelligence gathering techniques comes from pulp fiction, the United States would gather more information more reliably, without playing into the propaganda of hostile forces, and at considerably less moral hazard.
Every time I turn on the news I am reminded that the U.S. has no intelligence on ISIS except what they can get from drones and from satellites and from NSA based telecommunications monitoring that collects nearly everything but nets nearly nothing because groups like ISIS and al Qaeda have relied on personal couriers for high level communications for a long time now.
The idea of learning a culture and a language and a religion, and getting to know somebody's landlord and do them or their families some really nice favors so that they might grant admission to someone's apartment under the guise of maintenance or just on the sly, and in general cultivating networks of local informants (whether through intermediaries or directly), who do their best for you because you have demonstrated your trustworthiness and helpfulness to them, seems woefully absent.
If you have enough eyes and ears in the right places and friends who can give you access to homes and businesses, or who can simply notify you when strangers behaving strangely pass through or where and when they meet, you might not have to monitor every radio frequency in the world 24 hours a day, accumulating such vast backlogs of (nearly all useless) information that takes so long to sort through and analyze that timely intelligence is nearly impossible to come by, much less to act on.
Who says Abu Ghraib worked? The troglodytes and perverts who ran it? I don't trust their judgment. See my earlier comments.