Man Haron Monis' violent siege in Sydney raises questions about how a person with his criminal history was released on bail and able to carry out the attack. While his actions were driven by delusion and narcissism, they still meet the definition of terrorism. The Islamic State has actively encouraged "lone wolf" attacks in Western countries by troubled, alienated individuals. They view damaged people as weapons to enact violence without being formally connected or following orders. This poses challenges for detection without established patterns of terrorist planning and networks. Increased community engagement and intelligence sharing between security agencies will be important to address the threat of future lone wolf attacks.