Torture considered as an information industry:
For torture to be effective as an information-gathering method, it has to be institutionalized and used broadly. This is what I mean by aggregation. The information comes from observation of patterns generated by aggregating what the individual victims say and less from the words of an individual torture victim. Meaningful information from torture necessarily comes from torture's institutionalization.... But, while you could possibly verify concrete things like a weapons cache through torture of one person, you can't verify an alleged plot and its full details without torturing broadly and collecting the bits of information - sorting out the consistent from the inconsistent - into a patterned narrative.
You can’t torture one person because they are unlikely to know everything. You don’t know exactly how many people you need to torture because you don’t know the dimension of the threat: that’s why you’re torturing people in the first place. So you torture on a large scale and torture people who have nothing to do with the group you’re targeting.