Th e broadcast business principally implicates three areas of antitrust law. First, joint activities among broadcasters can raise questions under antitrust statutes that prohibit agreements that unreasonably restrain trade. Second, single fi rm conduct that excludes competition can raise questions under antitrust laws that prohibit monopolization. And third, broadcast combinations can implicate antitrust merger clearance laws that bar acquisitions that may substantially lessen competition in a line of commerce.