DRM (Digital Rights Management) is used by copyright holders to impose limitations on the usage of digital content and restrict activities like making backups of DVDs or remixing works. While intended to stop piracy, DRM often interferes with legitimate uses. The iTunes store offers DRM-free music while other stores continue to use DRM. Creative Commons licenses provide more flexible alternatives to traditional "all rights reserved" copyright. Network neutrality is the principle that internet service providers should not restrict users' access to content or favor certain applications.