The problem is, there's an easy way to break that. If you toss a ball so that it lands in the yard, it's in a place you can't access: from your point of view the ball has vanished. Then you can break the Fidelius for certain purposes by figuring out the general neighborhood and then tossing conjured balls everywhere, then picking up all the ones you can find (magically) and counting them. If you're missing a ball, it's because you can't find it, so there's a Fidelius or equivalent nearby. Repeat on smaller scales until you've narrowed it down to a particular house, then Fiendfyre.
Oh, absolutely, that is a way to break it. It requires a certain level of logic that most of the wizarding world lacks, but sure.
Did anywhere state that it was perfect?
Or, more on point, do we know if people even remember the general location of the neighborhood? I didn't think that they could. If they don't remember the general location, how would they narrow it down?
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 96. The previous thread is at almost 300 comments.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system.
Also: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, .
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: