This dissertation is my exploration on an economic analysis of some emerging cyber law and policy issues. I focus on three topics corresponding to some of the most contentious pieces of law: copyright infringement, intermediary immunity, and antitrust. Chapter I presents a welfare evaluation of the widely adopted content takedown policy that secures copyright in cyberspace. Chapter II studies the optimal mediation design where disputants are asymmetrically informed and hard evidence can be acquired or presented with a cost. Chapter III discusses how a profit cap, imposed via taxation on a group of firms, can improve efficiency for both vaccine sharing and platform competition.