Among other things, the Digital Millennium Copyright Act (DMCA) prohibits circumvention of technological measures that control access to copyrighted works. However, the DMCA requires the Copyright Office to periodically provide exemptions to this prohibition so as to allow persons to make noninfringing uses of certain works, where access to such works would otherwise require prohibited circumvention.

The DMCA provides that any such exemptions determined by the Copyright Office are valid for three years only, and a new rulemaking must be conducted every three years to determine whether to keep the existing exemptions and/or to add any new ones. The Copyright Office has just begun its fifth three-year rulemaking proceeding, soliciting comments on proposed exemptions for the next three years.