Why were they guarding the prophecy in the first place?

[bciss1]

No: HPFGUIDX 130957

I don't think it makes sense that they would have just stopped 
guarding it after what happened to Mr. Weasley.  After all, the attack 
on him just proved that Voldemort could somehow get in.  But I wonder 
why they didn't just destroy it in the first place (I know, then we 
wouldn't have had that whole book).  Dumbledore knew what it said, so 
the order didn't need to keep it around, and it would seem that the 
best way to keep anyone else from hearing it would be to destroy it.


Bciss1