To Those Who Would Follow the Leads Provided by Torture...
... which is a subject that is always relevant, but particularly these days to Canada's CSIS...
I would point to a quotation I heard recently in this documentary:
Why do you search so diligently for sorcerers?
Take the Jesuits - all the religious orders - and torture them. They will confess.
If some deny, repeat it a few times. They will confess.
Should a few still be obstinate exorcize them, shave them, only keep on torturing. They will give in.
Take the canons, the doctors, the bishops of the church.
They will all confess.
-Friedrich von Spee, Jesuit priest of the early 17th Century, with regards to the Inquisition.