Extent of blood protection (was Re: shortest stay at Privet Drive)

[Hannah]

No: HPFGUIDX 125582


> GEO commented: 
> > We've seen Hogwarts getting compromised more than Privet Drive 
> > including Peter Pettigrew as Scabbers, Quirrelmort, Voldemort's 
> > Diary/Lucius Malfoy, Sirius Black and Barty Crouch Jr. However 
in  comparison, Privet Drive has been compromised a total of once.
> 
> Eustace_Scrubb wrote:
> Does the ancient magic protect Harry against attacks by _anyone_ or
> just attacks by Lord Thingy?  If the latter, and if the dementor
> attack in Little Whinging was in fact ordered by Umbridge on her 
own,
> I'm not sure I'd say that Number Four Privet Drive has been
> compromised yet.
<snip>

Hannah:  
I think it must just be against Voldemort, or maybe those closely 
allied to him (Death Eaters etc.)  Or against dark creatures (since 
everyone seemed to think he'd be safe from the Dementors inside the 
house).
> 
Eustace Scrubb:
<snip>
> The problem I see with this now is the use of the word "there" to
> qualify the statements:  "_there_ you cannot be touched or harmed" 
and
> "whilst you are _there_ he cannot hurt you."  This does seem to
> suggest that the protection is limited to the _place_ where the
> Dursleys live.  At its most specific, this could mean "within the
> walls of their house."  But their home could be interpreted to mean
> "within their property lines" thus including the yard and the
> driveway.  It could even extend to the "Privet Drive neighborhood" 
or
> "Little Whinging."  That's about the broadest definition that seems
> useful, though perhaps others could argue for even more latitude
> (Surrey? England? UK?  Aargh!).
> 
Hannah: I reckon it's limited to the house.  Following the Dementor 
attack, Mrs Figg rushes Harry home, and he is ordered strongly by 
Sirius and Mr Weasley to stay inside the house.  Thus it would make 
sense that he is safe within the property.

Eustace Scrubb:
> But let's assume "there" is limited to the corporate limits of 
Little Whinging.  If so, why couldn't Quirrelmort touch Harry in the
> catacombs beneath Hogwarts?  Is the Privet Drive protection 
separate from the direct protection due to Lily's sacrifice?  Does 
the latter mean Voldemort can't touch or harm Harry anywhere?  If 
so, what use was the Privet Drive protection--at least until 
Voldemort's
> resurrection in bodily form, after which he _can_ touch and harm 
Harry (I think Imperio and Crucio constitute harm)?
> 
Hannah:  I think the Privet Drive protection is separate from the 
blood protection.  LV overcomes the latter at the end of GoF, when 
he is able to touch Harry.  Yet Harry still has to return to Privet 
Drive that summer, and even the following summer, reason given: for 
the protection.

Eustace Scrubb:
> But even if the Lily protection is gone while the Privet Drive
> protection continues, if it's limited to the Dursley's home area it
> seems to be of relatively little use to Harry on its own.  When he
> lived there year-round, sure, but now he tries to stay "there" as
> little as possible--and will apparently be there even less in 
HBP.  So exactly what good is it anymore?

Hannah:  It provides JKR the chance to show poor old Harry being 
treated mean by his Road Dahl-esque relatives ;-)  I don't really 
know what the reasoning would be behind his need to return, unless 
there is some aspect of blood protection we don't yet know about.  
Or unless there's another reason altogether...

Hannah