According to copyright laws of content use, authors’ get protection against their work being used by anyone publicly without permission or without giving them the deserved credit for it. If you want to use another author’s content, whether it is published anywhere or not, in some cases, you should get a written permission or at least give the author credit by mentioning the source of content along with the author’s name.
Keeping copyright laws in mind when plagiarizing is also important because you can be held responsible for it and can even be sued for using the content without permission or without crediting the original author. Although these rights vary in different parts of the world, the fact that it is unethical cannot be denied. Moreover, copyrights are updated on a regular basis. You might bypass them at some point in time; however, as soon as the copyrights change in your part of the world, you can be in a difficult situation.
Secondly, in case the author whose content you are using as plagiarism belongs to a country like U.S., where copyrights of content are strictly followed, they can easily sue you and you might have to pay heavy fines against such a crime. At that point, it won’t matter what country do you belong to and what laws are being followed there; what would matter in this case is what country does the original author belong to.
Copyright laws, where followed, protect the original author against his/her work being reproduced, derived, distributed or displayed without permission or without giving the respective credit to the author. On the other hand, it is not restricted to use others’ content at all. After all, information is meant to be shared. However, how to use t is what one should have a clear idea about. If you are using another author’s content for educational purpose and not for commercial use, the author as well as the copyright law might not have any objection at all. Another factor is the value of the work being copied.
So be careful and stay safe when using content from different sources!