A significant proportion of the academic literature on extremism online has sought to address its use as a tool for radicalisation and mobilisation by extreme Islamic groups. In so doing, the research neglects the significant, long-established—and growing—threat posed by extremist Christian groups, some of whom are amongst the most well-established—and sophisticated—users of digital technologies as tools for recruitment and organisation.Focusing on violent Christian groups, and the activities of anti-abortion activists in particular, this chapter seeks to offer an overview of the use of the internet by these groups that identifies not just common patterns of usage that are shared with other extremist groups but also the novel elements of their use of digital technologies alongside a discussion of the risks and policy implications this suggests.