Citing the source does not make things okay legally or ethically. Fair use allows one to use just enough content to give context, and you should never copy and paste things in whole. If you want to quote someone, a small snippet of text, example image, or short video clip and link back to the original is fine. Copying the entire article, image, or video is copyright infringement. Steemit should implement a filter or automated system that compares submitted content to what it can find already existing on the Internet (humans would have to be involved to compare things in print I suppose) and if the Steemit account cannot prove they have license to use the content here, payouts should either not be made at all or to a charity voted on by the witnesses or community as a whole.