Why not floo .. to London? Belief vs Reality

[severelysigune]

No: HPFGUIDX 91685

bboy_mn wrote:
<snip>
<< Now the exceptions-
We have seen that you can Floo/fire travel with in the castle; Snape
calls Lupin to his office using the fire, and once called, Lupin
arrives in Snape's office by fire. But travel within the castle would
not be much of a security risk. So, that acception seems reasonable.>>
<snip>

Sigune throws in:
On the other hand, "Floo-inside-Hogwarts" makes it rather easy, I 
should think, to break into teachers' offices - or doesn't it? I am 
just thinking of Snape in GoF, whose office was broken into by Fake!
Moody.
I can't remember our arriving at any final conclusions about the 
restrictions of Floo use, but unless these also apply to the 
fireplaces in teachers' offices, it is odd that there are no more 
raids on Snape's supply cupboard.

Yours severely,

Sigune