In his fourth triennial rulemaking under the Digital Millennium Copyright Act (DMCA), the Librarian of Congress has delineated six new classes of works that will be exempt from the DMCA's anti-circumvention provision. According to the DMCA, "[n]o person shall circumvent a technological measure that effectively controls access to a [copyrighted] work," without permission from the owner of that work. However, the DMCA offers an exception to this rule for "persons who are users of a copyrighted work which is in a particular class of works, if such persons are, or are likely to be in the succeeding 3-year period, adversely affected by virtue of such prohibition in their ability to make noninfringing uses of [a] particular class of work." The Librarian determines which classes of works are subject to this exception. The six new exempt classes include, inter alia, third-party applications that a person downloads onto a smartphone (aka "jailbreaking") and another that allows mobile phone owners to bypass phone locks in order to switch providers.