Actually the previous assertion predates 4chan. Anecdotally I recall using "copypasta" in the late 90's when working with code that had obviously been copied from another source and turned into a a spaghetti code mess. I don't doubt that it has taken on many other meanings, but I know for a fact that it means what naikrovek is not alone with that definition.
Yes. My exposure to the term is from slashdot and IRC in the late 1990s.
Can't believe I got downvoted for having more time on the internet than some others here, learning during that time, then making a statement based on what I learned.