House Elfs - why DID Dobby help Harry?

[kneazle255]

No: HPFGUIDX 81995


Kneazle255 wrote:
 i have questions about Dobby's motivations in CoS.  There is no 
overt reason why Dobby would think Harry was in any particular 
danger. Dobby knows about the diary. The diary's purpose is to kill 
muggleborns. Harry is not muggleborn. Why does he assume Harry is 
in mortal danger?
 
 Lucius' apparent purpose is to get DD out of Hogwarts and 
discredit the Weasleys.  There is no hint that Lucius knows that the 
diary has its own will or that it is capable of bringing Riddle 
back. I think Lucius would have used the diary differently if he 
realized it was a means to bring back his Dark Lord.)
 
If Dobby knows what Lucius knows and no more, his motivations 
don't make sense. He has to know more than Lucius.  He WOULD know 
more if he were orginally a Potter elf.

dcyasser wrote:

Harry knows at this point that Voldemort is a threat to him - he 
just doesn't know how much of a threat.  Dobby does. And Dobby will 
go to any lengths to protect Harry, and therefore the whole WW (EW?) 
from Voldemort.  
Plus, Dobby really, really, really likes Harry.    
Now, if Dobby knows, does Lucius know?

Kneazle255:

I pretty certainthat Dobby knows more than Lucius. In the polyjuice 
scene Draco states pretty clearly what Lucius intends-- Kill 
mudbloods and get rid of Dumbledore. And Draco never says he hopes 
Harry is going to die. He does hope Hermione is killed.

My first thought was Dobby was originally a Potter elf, but what if 
there were some sort of House Elf information network?

I know house elves aren't allowed to betray secrets about their 
families to other wizards, but what if they talk amongst themselves?