This report concerns itself with terrorist technical innovation, particularly with regards to terrorists’ incorporation of emerging technologies into their practices. More specifically, it investigates, through the elaboration of a theoretical learning framework, how terrorist groups can adopt the practices of ideological enemies operating in different security, ideological and political environments. It does so through a study of three cases of emerging technology use by Islamic State (IS) and racially and ethnically motivated violent extremists (REMVE), which shed light on why ideologically diverse groups might adopt practices from each other.