In support of what everyone else have said, outrightly copying and pasting a post belong to another person outside the forum, even if the user references the original post by sharing a link to it, but fail to include his or her opinion concerning the same post he or she copied, and as well, ask the community's opinion as well, then, that is a clear plagiarism, nothing else it can be called.
I myself do sometimes copy posts from other sources, but I always make sure to do it in such a manner that the post I copied looks like it's a reference to my own point I'm making, or question I am asking the community, I don't just copy people's post and post word for word, without saying anything any thing of my own, that is clearly wrong and a clear plagiarism.