Copyright law aims to balance promoting new creation with allowing use of existing works. However, over time the law has shifted to favor copyright holders through longer terms and harsh penalties. Fair use provides an important escape hatch as a flexible legal doctrine that allows unauthorized use of copyrighted works in some circumstances. Communities actively define fair use for themselves through codes and best practices in areas like documentary filmmaking and online video. This helps expand what projects can be done while reassuring individuals and organizations regarding their fair use rights.