Muslims Against Crusaders (MAC) was the last reincarnation of Al Muhajiroun. Some of its members travelled to Syria and joined ISIS and others have been arrested the British security services. Most research on Al Muhajiroun and its reincarnation tend to focus on socio-political and economic circumstances allied with Salafi/Wahhabi Islam, to explain the motivations to join extremist groups. However, such explanations fail to account for the role that collective strain, vicarious strain and linked fate have on individuals deciding to join MAC. This paper argues that the experience of collective strain, collective strain and linked fate by members of MAC contribute to them deciding to join the group.