Well, if you read through all the comments above, you'll find various opinions. In my personal opinion, while citing the sources is better than not citing the sources, simply copying and pasting from other sites is not cool. It hurts the Steemit platform by reducing the percentage of original content and therefore lowering the platform's value compared to other websites. For a much better explanation of that point, see this post by @cheetah, paying particular attention to the section titled "Why is copy-paste "bad"?"