This is an interesting question from the Post and Courier, Charleston. Do you notify someone if you're going to use their tweet?
Industry sites sometimes embed my tweets and I get a surprise when I see them - but I take the view that I've said it in public and so it's fair enough.
But what about when it's friends posting tributes on a Facebook wall that happens to have a public profile? These get ripped off all the time.
As to whether we should ask people if they post on a newspaper's Facebook wall if they mind being published, I think not, although the Daily Post does tend to say 'we'll publish a selection' when posting something soliciting feedback.