I believe Harry considers some punishments completely out of bounds, too severe for anyone. Certainly I do. The following may have no connection to the real reasons for this; but even without Many-Worlds you have a non-zero probability of personally suffering any possible punishment. Legally allowing a given punishment for anyone seems to produce a non-zero increase in this probability (even in a world without Polyjuice). Some possible punishments may have such negative utility for you that a course of action which avoids such increases, but which almost certainly leads to your death, would still have positive utility. Azkaban seems like a good candidate for such a punishment.
Furthermore even if one is a pure consequentialist, there may be a case for acting like a deontologist in some cases. While a perfectly rational entity can properly weight costs and benefits, people can't. Chances are if a person's moral code says "it's a good idea to subject some people to mind rape for decades" that person has made a mistake, and one should account for that.
- This thread has run its course. You will find newer threads in the discussion section.
Another discussion thread - the fourth - has reached the (arbitrary?) 500 comments threshold, so it's time for a new thread for Eliezer Yudkowsky's widely-praised Harry Potter fanfic.
Most of the paratext and fan-made resources are listed on Mr. LessWrong's author page. There is also AdeleneDawner's collection of most of the previously-published Author's Notes.
Older threads: one, two, three, four. By tag.
Newer threads are in the Discussion section, starting from Part 6.
Spoiler policy as suggested by Unnamed and approved by Eliezer, me, and at least three other upmodders:
It would also be quite sensible and welcome to continue the practice of declaring at the top of your post which chapters you are about to discuss, especially for newly-published ones, so that people who haven't yet seen them can stop reading in time.