Using the Minuteman Civil Defense Corps as a case study, this work explores the emergence and recent proliferation of civilian border patrol groups at the US-Mexico border. It is shown that the emergence of these groups can be linked, on the one hand, to an increasing criminalization and securitization of immigration. On the other hand, it is shown that it can also be connected to globalization and its associated forces of political and economic liberalization, which have transformed the security landscape in such a way that this form of citizen activism is not only tolerated, but arguably even encouraged.