Technological protection measures, or “TPM” are security measures added to digital technology and content by content providers in order to restrict and control access, and exert greater control over the uses of the content they sell.
TPM is a broader term than “DRM", which really refers only to software-encoded protections. TPM is potentially both software and hardware based. Measures could include requiring passwords, filtering software, censor chips in computers, monitoring/ surveillance technology, (semi-)autonomous software tools and more. Regionally coded DVDs and DVD players are one example of a TPM. Other examples are Microsoft’s “Trusted Computing” and the “feature” of Apple’s iTunes that permits users to transfer a song to only five different computers.
While ostensibly aimed only at infringing users, TPM techniques often have negative impact on legitimate users, both with respect to legal uses and to privacy concerns. However, under at least U.S. law, it is illegal both to circumvent any technological protection measure and to possess anything that makes circumvention possible. The potentially sweeping nature of TPMs has led some to argue that TPMs make it possible for a rights-holder to not only enforce their copyright, but to exert control over a work that exceeds the limits of what copyright law permits.