In a continent plagued by violent conflicts, the emergence of non-state security actors has become a significant phenomenon, particularly in Nigeria's Borno State, where the Boko Haram insurgency has severely strained formal security institutions. While these volunteer groups, like the Civilian Joint Task Force (CJTF), have played a critical role in complementing government counter-insurgency efforts, their rise has created a dual security threat for civilians. This study, therefore, explores the nature, causes, and consequences of human rights abuses by these groups in Borno State. The study adopted a mixed-methods research design, using both quantitative (questionnaires) and qualitative (KIIs and FGDs) approaches. Data were collected from a purposively selected sample of 377 respondents in three significantly affected LGAs: Bama, Monguno, and Gwoza. The findings revealed that NSVGs emerged as a community-driven response to the state's failure to provide adequate security, driven by a need to protect against persistent Boko Haram attacks. However, their involvement in human rights abuses was primarily caused by a complex combination of factors, including a lack of formal oversight and accountability mechanisms, coupled with a perception among members of being above the law. The study concludes that while these groups are a vital protective hedge for communities, their lack of regulation and oversight has led to widespread abuses, including arbitrary arrests and extrajudicial killings. Therefore, the study recommends that the government urgently implement strict oversight mechanisms, clear rules of engagement, and continuous human rights training for all NSVG members to ensure accountability and restore public trust.