Building on theory within anthropology and associated fields, I develop feralness as a lens for understanding the complexity of technological afterlives. Conceptual development proceeds through a case study of the relationship between Do-it-Yourself Biology (DIYbio), nonprofessional scientists experimenting with the established technology of recombinant DNA in new contexts such as garages and kitchens, and the Federal Bureau of Investigation (FBI). Absent the institutional controls of academia or industry, DIYbio has been perceived by the FBI as a potential threat to national security and is policed by the FBI’s Weapons of Mass Destruction Directorate. Though the FBI has tried to contain the spread and reach of DIYbio, it has, ironically, came to be one of the main instruments of DIYbio’s global spread. In closing, I argue that feral technologies, those technologies with unexpected and potentially dangerous afterlives, are emblematic of the 21st century.