Concerns over practices in cyberspace are central to the consolidating international agenda for cybersecurity. Responses to such concerns come in different shapes and sizes, and are proposed by different actors. Whether it concerns intellectual property rights, the theft of trade secrets, collection of personal data, critical infrastructure protection, DNS security, or geopolitical issues, the rise of cybersecurity as a multifaceted global issue has led to the proliferation of governance mechanisms aimed at responding thereto. While state efforts have sought to promote norms of responsible state behaviour in cyberspace, we argue that technology companies are also taking the lead as norm entrepreneurs in the context of the stability and secu...