The authors of this paper consider recent developments involving terrorist use of the internet and cyberspace for a range of purposes, as well as renewed concerns relating to potential terrorist attacks against critical infrastructure and their control systems. Following from an overview of recent trends, they discuss public and private efforts to respond to existing and emerging threats. The authors anchor these within the context of current efforts to manage a range of interrelated cyber security challenges, focusing predominantly on the international and regional response, as well as efforts by industry actors to deal with terrorist use of their products and services.