Filing an amicus brief, the Progress & Freedom Foundation (PFF) told the D.C. Circuit Court of Appeals that the FCC’s exercise of ancillary jurisdiction in an order that held Comcast liable for violations of the agency’s net neutrality principles “greatly expands the Commission’s authority by regulating a communications service that is not an adjunct to and therefore closely connected to services that the Communications Act explicitly places within the agency’s regulatory powers.” Written for PFF by law professors connected with Northwestern University and the University of Virginia, the brief filed with respect to Comcast v. FCC addresses the FCC’s August 2008 ruling that Comcast “unduly interfered with Internet users’ right to access the lawful Internet content and to use the applications of their choice” by “throttling,” or temporarily blocking high bandwidth peer-to-peer file transfers originating from BitTorrent and similar websites. Supporting Comcast’s claim that the FCC’s decision should be vacated as “legally inappropriate,” the PFF brief contends that the agency improperly expanded its authority by imposing regulation on a communications service that is not an adjunct to any of the services that fall within the FCC’s regulatory reach under the 1934 Communications Act. Arguing that any attempt by the FCC to exert jurisdiction over an adjunct service “must still be tied, with the necessary closeness, to its explicit powers over the regulated services,” PFF stated that there is nothing in the Communications Act that grants any authority to the FCC to regulate Internet services. Accordingly, PFF declared: “the exercise itself—of looking for hints of authority scattered throughout the Act—should have convinced the Commission that Congress did not actually delegate its authority to make law for Internet services.”