I can understand the Creative Commons license pretty clear-cut when it comes to normal content visible anywhere on the network, but does anything change when that content has been deleted? I've recently run into a situation where I'd like to reference some content from a question which has since been deleted, and I'm not sure how exactly that content is covered by the license.
Most notably, how does it affect attribution? Sometimes users delete things as an alternate method of dissociating the post from their account without actually having to hassle the Stack Exchange team with manually removing their ID. I don't want to go and disrespect their wishes by directly saying "this content was posted by this user here" if they don't actually want to have their name referenced. As a moderator, I could post a comment on the deleted post and ask if they want to be attributed, but a) that seems like a slight abuse of the privilege and b) they'd have to undelete the post to respond to that comment (which isn't even possible if the question is also deleted). So there's no effective way to communicate with the user to ask them outside of posting off-topic comments elsewhere or hoping to catch them in chat.
Similarly, who exactly are we supposed to attribute if the user has since been deleted and there isn't anyone to attribute anymore? Just go with whatever the plain-text name is? State the account has since been deleted?