The development of digital network technologies simplifies and speeds reproduction and distribution of copyright works. Anyone who has access to computers, mobile phones, and the Internet can simply obtain, exploit, and disseminate information without copyright owners’ authoriza- tions. Rampant piracy, however, has made copyright owners distrust the effectiveness and enforcement of the original copyright legal regime that was born and developed in a paper and analog technology age. Copyright owners began to widely adopt digital rights management (DRM) and tech- nological protection measures (TPMs) to impede access to and use of their works without their authorizations. These self-help measures did effec- tively stem piracy at the beginning, but as hacking technologies and de- vices were developed to circumvent or undermine original DRM, such self-help measures were no longer able to perfectly protect copyrighted works. The same copyright owners who once sat back and relaxed, trust- ing in self-help DRM technologies, again had to lobby their governments to enact new legislation that could protect the existing technological mea- sures against circumvention. Anti-circumvention law was thus promul- gated to satisfy copyright owners’ interests for strong copyright protection in the digital network era. The protection granted to DRM and TPMs, then, is related to but quite different from copyright protection. Copyright law is the first layer that protects copyright owners’ exclusive rights from the legal aspect; DRM and TPMs are the second layer of protection from the technological aspect; and, finally, the anti-circumvention law is the third layer that protects the DRM technologies.