" If you're posting anything you did not create yourself or do not own the rights to, you agree that you are responsible for any Content you post; that you will only submit Content that you have the right to post; and that you will fully comply with any third-party licenses relating to Content you post." this is from Steemit terms of service, they say nothing about credit they just say you can only post content you have the right to post. I have the right to post content from Unsplash without crediting because the website allows you to not give credit. So I should not be getting comment about plagiarism, if steemit terms of service change and they require you to give credit for every photo I will comply, but until now I didn't break any rules