I have to point out, you've made a mistake of terminology here, one frequently pointed out at Language Log. You seem to have used "passive voice" to mean "construction that is vague as to agency". It's important to note weaseling, as you point out, but the use of passive voice isn't a good heuristic for that. Consider your own example of "Unreliable elements were subjected to an alternative justice process"; little of the weaseliness comes from the use of the passive. It wouldn't be much less weaselly if written as "When dealing with such unreliable elements, those responsible apply an alternative justice process." Who's responsible? I dunno.