I would like to ask whether I can use stock free licensed images from the internet in my course?
I'm also planning to do a bit of animation in my course but as you all know it takes alots of efforts to draw scenes for animation, I am thinking of blending different free licensed stock vector illustration for my animation.
Your suggestions mean alot thank you!
It depends on the specific license terms for the content you are thinking of using, and whether those terms came from the original creator of the content or someone else who uploaded their own copy of it. Can you point us to an example?
The problem is many images on the free sites are actually copyrighted and someone just stole them and uploaded them.
If the owner finds out you are using it they can (and will) sue you and win.
You are responsible for ensuring the media you use is actually cc0 or you have paid for it.
I completely avoid cc0 sites, pay a little and get clean ones and from a site with insurance.
"Small modifications" are considered "derivative works" and won't necessarily let you avoid licensing issues, but you're getting into the world where you'd be better off talking to a lawyer.
Freepik.com doesn't appear to really be free - you have to subscribe in order to get "commercial" licenses, and even then you can't be sure that freepik.com actually has the license they claim to have for the image. I'd consider pixabay to be a bit more reputable, but you run the same risk there.
The point is anytime you use someone else's content you are taking a risk. The least risky approach is to only use your own original content.
What I do personally - on the advice of my own lawyer - is subscribe to istockphoto.com. If I can't create an illustration on my own, I'll use one from there where I can prove I have a legitimate license for it. For really specialized things that don't have stock images, I'll sometimes use content from Wikimedia Commons after being very careful to comply with any usage and attribution requirements listed there.