The selective depletion of specific bacteria from complex microbial communities may provide an alternative to broadly acting antibacterials; however, the development of such targeted approaches has been slow. Bacterial-mediated contact-dependent killing via the type VI secretion system (T6SS) may be a feasible strategy, yet the T6SS targets cells indiscriminately. To overcome this limitation, Ting et al. developed programmed inhibitor cells (PICs) that express nanobodies on their surface that mediate cell–cell adhesion via antigen recognition. The authors showed that targeting a unique natural cell surface antigen resulted in the selective killing of target cells in a complex community in liquid medium. Finally, resistance to PIC-mediated killing seems to emerge slowly, which is encouraging for the development of PICs for medical applications.