Mass digitization of library collections is revealing works in the public domain and orphan works whose copyright owners cannot be found. This puts pressure on copyright law to adapt to new digital possibilities. The University of Texas Public Domain Project identifies works that are public domain and develops best practices for searching for orphan work owners. While some assume everything online is public domain, copyright actually still applies unless a work explicitly gives permission. Authors implicitly license limited use by posting works, and individuals can be liable for distributing copyrighted works without permission. Fair use allows for limited use of copyrighted works for purposes like education or commentary.