To answer the poll question... if you are copying and pasting, it should be noted "copy and paste" or " i found this link " etc. I have done it before, who cares. Because not everyone knows everything.
It depends on how germane the copy and past is to the discussion. If you are arguing about hgh and toenail growth, a "Your toenails and HGH" on pubmed would be fine. But logical stretches shouldnt be presented as definitive....though i still like to hear them.