Fidelius (long, contains spoilers for PoA and OtP)

[justcarol67]

No: HPFGUIDX 95028

Wildean wrote:
<<<<snip> 
As we know, "The information is hidden inside the chosen person, or
Secret-Keeper, and is henceforth impossible to find—unless, of course,
the Secret-Keeper chooses to divulge it."  Dumbledore has used the
Fidelius charm to conceal 12 Grimmauld Place, particularly in its
aspect as the HQ-Quarters of the Order of the Phoenix. Presumably,
members of the Order of the Phoenix know where they're based, as part
of the secret that's being Kept. 
 
But if anyone outside the Order finds out, then the secret is divulged
and the place is no longer protected by the Fidelius charm. But there
are several non-members of the Order of the Phoenix who know all about
12 Grimauld Place, and the fact that it's the Order's HQ. Namely Harry
Potter, Ron, Fred, George and Ginny Weasley, Hermione Granger,
Kreacher, Mrs. Black's portrait.
 
I'd say pretty much that constitutes divulgence. In that case, what's
protecting 12 Grimmauld Place now?>>>
 
JoAnna responded:
<snip>  I don't think anyone BUT the Secret Keeper can divulge the
wheareabouts of the location under the Charm. IMO, the words "The
Headquarters of the Order of the Phoenix are at 12 Grimmauld Place"
could have been flashed on the scoreboard at the Quidditch World Cup,
but no one would have been able to find it unless Dumbledore himself
had done the flashing. I believe this because of what Flitwick (?)
said in the Three Broomsticks: "You-Know-Who could have had his face
pressed against the Potters sitting-room window and he still wouldn't
have been able to find them!" So, even if you know the address of the
location under the Fidelus charm, it won't do any good unless the
Secret Keeper tells you where the location is. So, even though Harry,
Hermione, et. al. know where headquarters is, they could put a post in
the Gryffindor common room and still no one could find the Order
Headquarters.

Carol:
I agree with JoAnna, but I'd like to add a few words. IMO, revealing
the secret to the Weasley children, Harry, and Hermione doesn't
constitute "divulgence" because I don't think that the Order members'
knowledge of where they're based is part of the secret. I think that
once DD had been made the Secret Keeper, he had to tell the members
personally where the headquarters was, even if they had known it
before. The Order members can't tell Harry, even though they know the
secret. They can only take him there. Then Moody hands him a scrap of
paper in Dumbledore's writing. Not until he's not only read but
memorized the words on the paper can he see the house. Dumbledore has
told him the secret. Then Moody burns the paper so that no one else
will find it. (Even a Muggle, reading that paper, *might* be able to
see the house.)

Harry, as I understand it, can't reveal the secret even though he
knows it, even if, as JoAnna said, he displayed it on the scoreboard
at the QWC (a bit of an anachronism, but it makes the point ;-) ).
Neither can the Weasley kids or Hermione. Kreacher is under direct
orders from Sirius not to reveal the secret. Even with Sirius dead, he
may still be bound by that promise. He would also, I assume, be bound
by the Fidelius Charm--unless for some reason it doesn't extend to
nonhuman, speaking creatures (it clearly doesn't apply to owls). As
for Mrs. Black's portrait, I confess that thought never occurred to
me. Maybe her unstickable charm (obviously I've botched the term!)
makes it impossible for her to move from portrait to portrait as
Phineas does, or maybe, unlike Phineas, she has only one portrait,
where she always remains. Also, as part of the house, I would think
she's part of the secret.

It's true that the Order members are in more danger before since those
who were at the MoM have now revealed their identity to Bellatrix, who
has undoubtedly reported them to LV. Also LV, through Lucius Malfoy,
probably suspects several others who were with Harry on Platform 9 3/4
in OoP, as well as the surviving members of the old Order, whose
identity would have been revealed to him by Peter Pettigrew. I haven't
kept count, but that's almost everybody except Snape, and he may well
be suspected, too. Still, even if LV knows *who* they are, the
Fidelius charm would still keep him from knowing *where* they
are--unless the spell doesn't apply to house-elves. In that case, the
Order had better change its quarters. Lucius may be in Azkaban, but
Narcissa isn't, and neither is Bellatrix.

Carol, whose definition of "a few words" clearly differs from
Dumbledore's!