Copyright law governs the use of materials found on the Internet and in other media such as books, video, and music. Once an expression is fixed in a tangible form, such as being posted online, it is automatically protected by copyright. Authors should expect their works to be read, downloaded, printed, forwarded, and used as the basis for other works, unless they specify otherwise through an express license. Individuals and institutions can be liable for copyright infringement when they copy and distribute others' copyrighted works without permission. The fair use doctrine balances authors' rights to compensation with public access to ideas, and allows for uses like research copies, coursepacks, and educational digitization of images under certain conditions. Users should check if a