This is a sensitive and quite controversial topic in Steemit.

Long story short, I have seen many posts where images, text and even video are quoted which are subject to copyright. I assume that many of these users believe that by simply crediting the source, they are safe, but they are violating the law, because if a third party's creation is copyrighted, I cannot profit from it on the blockchain, where I am getting "paid" for my posts.

In the middle of controversies, we can be safe in a case like this one you present us, in which I make use of a material that is public, to promote it. By giving more popularity to such material, the person, firm, company, etc., that creates, edits and/or produces it, sees it as a gain for themselves or as a mutual benefit, so we would be out of danger of being subject to a lawsuit with legal consequences that can be very severe.

Many people violate copyright laws because they are unaware that they are doing so. I hope that everyone acting in good faith is safe.

I hope this helps, @myblueworld :) But you can always find good information about it on the web. Cheers!