Since medieval times politicians have argued that harsh punishments (such as drawing and quartering, torture and the like) has a substantial deterrent effect on criminals.
Some philosophers disagree that such punishments actually deter such behavior.
I was told by ThruGog that "the way most wizards speak about Azkaban certainly seems to indicate its effectiveness as a deterrent" (The Politics of Harry Potter).
Do wizards (perhaps we can restrict to British ones from 1991-1998) think Azkaban is effective (whether or not it actually is)?
What textual evidence suggests that rank and file wizards support the use of their methods?