Cyber terrorism has not been specifically prohibited or criminalized at the international level. Nonetheless, there is no lacuna in international law that leaves cyber terrorism completely unregulated or unpunished. This chapter surveys the legal framework governing cyber terrorism at international law, considering both existing sectoral and regional anti-terrorism treaties, and the incomplete UN Draft Comprehensive Anti-Terrorism Convention. It then questions whether there is a need for an international cyber terrorism instrument. The utility of such an instrument will depend on the gravity of the threat of cyber terrorism, the scale of technical challenges in addressing that threat, the stigmatizing value of such a convention, and the possible human rights implications.