Re: OOC
Atm, I'm working on the assumption that Snape doesn't know about Harry because, well, he doesn't (he and Draco haven't gotten that far in the thread yet). That was just residual resentment from the past few years spilling out, although the timing was absolutely perfect, I must admit. :-D
Dumbledore won't Obliviate anybody unless he absolutely has to. I mean, he didn't even Obliviate Snape after he overheard Trelawney's prophecy. (Of course, one could argue that was simply Machiavellian!Dumbledore who wanted to produce his Chosen One, no matter what the cost. *shudders*) He hopes that now -- since he can point out actual people they have endangered -- the kids will take him a little more seriously. He also hopes they will fess up on their own, but he is more than prepared to use Legilimency to find out who all knows or even suspects. *innocent grin*