In order to strengthen copyright protection against piracy in the digital environment, U.S. Congress enacted the Digital Millennium Copyright Act (DMCA) in 1998. One of the important regulations included in the DMCA is the anti-circumvention provisions which prohibits the development or use of technologies that enable circumvention of a technological protection measure attached to the digital content. Any person who violates the anti-circumvention provisions by cracking technological protection measure or by providing circumvention tools will be prosecuted unless his act of circumvention falls into seven exemptions provided by the DMCA. Because these exemptions are so limited and only cover a small part of legitimate copyright uses, whether a person can circumvent a technological protection measure to access and use copyrighted materials behind based on fair use claims becomes an issue when we try to clarify the connection between anti-circumvention regulations and traditional copyright laws. Additionally, two recent DMCA cases illustrated another intrinsically unexpected effect of the anti-circumvention provisions where the non-copyrightable product providers may use the DMCA to prevent competitors from developing compatible accessories by claiming copyrights on the computer programs embedded in the products and by claiming their anti-circumvention rights on the technological protection measure attached to the computer programs. This kind of application of the DMCA may raise concerns of DMCA misuse and unfair competition.