Is/are there lists of instances of "borrowed" or "foreshadowed" ideas or details between Harry Potter fan-fiction and Harry Potter books 5, 6 or 7 that were released later?
This question as stated in the title is a bit too broad and might sound inflammatory, so let me clarify the details that didn't fit into already over-long title:
This is not meant in any way to imply anything negative about J. K. Rowling. I'm interested in significant ideas or details that are identical or very similar, but not in speculation as to the cause (e.g. "brilliant insight by fanfic author" vs "Rowling read and subconsciously remembered" vs "Rowling stole the idea"). Having actual documented confirmation as to what was the cause (e.g. Rowling's acknowledgement) would be a neat addendum, but not a requirement.
Just to spell it out, I'm looking for significant and non-obvious ideas, details or events that occured in fanfics released before the relevant 5th, 6th or 7th book was released (e.g. post-Goblet of Fire fanfics that were released before HP5).
The idea/detail/event must be significant. E.g., the fact of an individual character dying is not really significant (including Dumbledore). Harry having to do the whole sacrificing himself thing is significant.
It must be non-obvious. Who married whom at the end of book 7, or Dumbledore dying in general, or Neville ending up as a hero are pretty obvious from previous books or as possible plot twists. So is "a giant climactic battle at Hogwarts" - not predictable from previous books per se but way too obvious. Or "lots of characters dying in book 7".
So if the list mostly consists of listing details like the examples above aren't what I'm looking for.
I'm specifically interested in pre-compiled existing lists, NOT turning this into a list of one-per-answer examples. The list should contain at least 10 items which are significant and non-obvious.
If you don't know of an existing list but know a lot of examples yourself, feel free to compile one off this site as a draft (e.g on Pastebin) and I would gladly verify if it contains enough valid entries; if so it would also constitute a valid acceptable answer.
NOTE: If the moderators feel that this last bullet is Bad Juju, i'll remove it from the question leaving only "Existing web lists only" #3.