I just flagged a question as off-topic on SO. On not getting the badge I checked here and gathered that apparently (seen no official comment) it's only awared for flagging spam/offensive. So... shouldn't the badge say so?
Oh, and given that, should it really be only bronze? I've only seen one spam post so far (not on SO), so I think they're quite a bit rarer than off-topic posts.
(Hmm, I do have to check where I (should) have gotten that CP badge...)