What is the ruling on downloading religious books for free from the internet when one is not sure if the author or copyright holder has given permission, and does the phrase "uploaded by so-and-so" mean that it was published without the author's permission?

Intellectual property rights are protected and may not be infringed upon. If books available online are uploaded with the permission of the rights holders or are not copyrighted in the first place, then it is permissible to download and read them. However, if they are copyrighted and were uploaded without the permission of their owners, then it is not permissible to download them. The presence of the phrase "uploaded by so-and-so" does not imply permission to publish. Some scholars have permitted personal, non-commercial use of copyrighted materials without the permission of the rights holders, especially for Islamic sciences, when people are in need and unable to purchase them.