Horcrux hunting

[whirledgirl]

No: HPFGUIDX 153163

Potioncat:
Many wizards can cast a Patronus.  Only the Order uses them for 
communication. Snape apparantly doesn't use them against Dementors. 
So perhaps he could conceal his Patronus from the DEs. Of course, 
it's still a theory that his Patronus will change. If it does, I'm 
not sure how we'll know...

Lolita:
There might be 50 wizards with phoenix patronuses out there, as far 
as we know. Or maybe I've forgotten the way that functions, in which 
case, feel free to remind me :)). 
<Snip>

WG*: 

What about the difficulty Harry has mastering how to even cast a 
patronus? I recall from what Lupin said that not every wizard can 
cast a patronus. Heck, not even every wizard can cast proper shield 
charms! Never mind ones (because in essence, isn't a patronus a 
shield against Dementors?) that can or can't produce a decent 
patronus in the presence of dementors! Has Snape even got a memory 
happy enough to create a patronus? Enough love, which seems to be 
the type of memory patronuses (patroni?) 'respond' to more? 
I suggest that maybe Snape has not got a patronus, revealing he is 
in fact not 'good', a real DE. This is why we haven't seen it, why 
it would give him away. 
Furthermore, there are two things throughout the series that stick 
in my mind regarding Snape - 1) DD says (in PS I seem to recall) he 
has a more brilliant mind, and that therefore his mistakes are 
accordingly bigger and 2) Harry is a good judge of character. PS, 
train journey. Rebuttal of Draco's 'friendship'. This is one of the 
first things we find out about Harry's personality, his integral 
character. The equivalent we have of DD, on the other hand, is him 
leaving the Dursley's literally on their doorstep.
ohhhpppss this always happens- didn't mean to write so much heh!!

WG*