I think you are confusing legal protections for intellectual property with plagiarism. (At least that's what I think you're doing if I read your comment as sarcasm and guess what you're trying to say non-sarcastically?) But they are entirely different things.
You can be violating copyright without plagiarizing, so long as you cite your source, but if you copy a copyright-protected work in an illegal way when doing so.
And you can be plagiarizing without violating copyright, if you have the permission of the copyright holder to use their content, or if the content is in the public domain and not protected by copyright, or if it's legal under fair use -- but you pass it off as your own work.
Two entirely separate things. You can get expelled from school for plaguriism without violating anyone's copyright, or prosecuted for copyright without committing any academic dishonesty.
You can indeed have the legal right to make use of content, under fair use or anything else, but it can still be plagiarism. That you have a fair use right does not mean "Oh so that means you are allowed to turn it in to your professor and get an A and the law says you must be allowed to do this and nobody can say otherwise!" -- no.
You can be violating copyright without plagiarizing, so long as you cite your source, but if you copy a copyright-protected work in an illegal way when doing so.
And you can be plagiarizing without violating copyright, if you have the permission of the copyright holder to use their content, or if the content is in the public domain and not protected by copyright, or if it's legal under fair use -- but you pass it off as your own work.
Two entirely separate things. You can get expelled from school for plaguriism without violating anyone's copyright, or prosecuted for copyright without committing any academic dishonesty.
You can indeed have the legal right to make use of content, under fair use or anything else, but it can still be plagiarism. That you have a fair use right does not mean "Oh so that means you are allowed to turn it in to your professor and get an A and the law says you must be allowed to do this and nobody can say otherwise!" -- no.