mpel the owner of three other ski areas located near Aspen, Colorado, to continue marketing a multiarea pass good for all four facilities. Although skiing facilities are not usually regarded as networks, it is possible to conceive of this arrangement as a form of interconnection access. The fact that the courts found Ski Co. liable thus provides some doctrinal support for mandating interconnection access under at least some circumstances. As noted earlier, Aspen Skiing has been heavily criticized. Indeed, the Trinko Court distanced itself from Aspen Skiing, calling it "at or near the outer boundary" of antitrust liability. After Trinko, Aspen Skiing can at most be read as imposing some obligation to assert a valid business justification before discontinuing a preexisting business relationship and refusing to allow a competitor to resell a monopolist's services at the full retail price (540 U.S. at 409). The Supreme Court thus flatly rejected the idea that Aspen Skiing could serve as the basis for granting access to a competitor with whom the network owner has not previously done business. There is thus little reason to believe that a court will issue a general mandate of interconnection access. 4. Platform Access Platform access requires network owners to open their networks to providers of complementary services sold through the network. It requires a network owner to provide carriage to any provider of a complementary service that presents its traffic at a designated interface in a standardized format. The early cases involved requests to force local telephone systems to open their networks to providers of long distance, information services, and CPE, described in Chapter 8. The current debate over network neutrality, described in Chapters 11 and 12, focuses on com- pelling broadband systems to provide platform access to all Internet content and applications providers. It is widely recognized that network owners already possess powerful incentives to provide platform access. That is because enabling customers t