Much depends on context. For example: If I want to demonstrate how many versions of the song "Caballo Viejo" exist (more than 200), it is perfectly legitimate to post a few YT samples that I did not create, so long as I use a link to the original video rather than copy it and re upload. The same is true when writing an article about past events, it's not possible to go back and create original images. Using a link to the original image is enough to credit the original poster since they allowed embedding in another website. This is a feature you can turn off should you not want to share images/videos in that way.
One of the issues is that Steemit is also touted as an alternative to YT and FB and one only has to look at FB to see why folks upload content that is not their own; on FB it's common place. I found a number of my original music videos copied from YT uploaded to other people's FB pages and there is little FB will do about it. This really sucks as I have to scour FB to find them and I'm out the views, likes and comments even if the thief's uploads are taken down, I won't get compensated while FB benefited from the traffic.
I don't have a problem with folks posting a link to one of my videos to another platform; after all, it drives traffic to my videos and I still get the views that increase my ranking. It's the copying and re uploading I have a problem with.
Greetings!
When you embed a Youtube video it's still on their site and they still get the plays. They positively encourage embedding. Just because someone puts an image online does not mean you can use it unless they specifically allow that. I just think we have to be careful that Steemit doesn't get a bad reputation. Enforcing such copyright is really hard, but if you mess with the wrong people they can come down hard on you.
Yeah, I brought that up when someone uploaded Hollywood movies. I stopped counting at 114 of them; that's a lot of potential lawsuits and Hollywood has the financial resources to make it stick. He has since stopped uploading as he was starting to rightfully receive flags for 100% plagiarism.