Convicted terrorists from Jemaah Islamiyah (JI) have attested to using the Internet in one way or another during their operations, from sending messages to one another to looking for extremist fatwas online to justify their actions. That said, however, one would be hard pressed to prove the primacy of the Internet in their transition to violence. More often than not, more traditional elements – blood relations and marriage ties – remain the key to individual religious radicalization and political violence in Southeast Asia. This paper revisits these kinship linkages as well as quasi-kinship ones that include teacher–disciple bonds and the wider fraternity of ikhwan-ship (brotherhood) with particular regard to JI. Keeping counter-terrorism efforts in context is important or else governments could run the risk of carelessly allocating vital resources to less immediate concerns.