Around when I first joined NextGenUpdate, I made a thread similar to this, or one that had the same point at least (Not insinuating this should be closed, just saying) and the feedback generally was that the majority of people couldn't care less as long as a source was posted.
My view, which isn't always right, is that copying and pasting of any sort, even when the source is given, is plagiarism. What someone copies and pastes is the hard work of another person. Depending on the depth of the post, they could have spent some time writing it - for what? Just to have a link to the page they wrote it on?
The thing that I had to comes to term with is that people post threads that are copied and pasted, for the most part, just to gain reputation. You have no idea how many times people will add reputation to a user if the thread seems developed. It's not always the fault of those adding reputation to the user, as they don't always know it's copied and pasted, but they will still get reputation.
As the saying goes, '

on't hate the player, hate the game'.
As long as there is reputation (which some people think matters) to be earned from it, they will post it.
Now, I couldn't care less. I have a list of people in my mind that I know, constantly copy and paste threads and take credit for them. As soon as I see their thread, I won't pay them the gratitude of a thread view.
It makes me think sometimes, why no-one has copied and pasted Einstein's theory of relativity and said it was theirs. I bet they would have a gold star by now...
//AC