With the rise of Islamic State of Iraq and Syria (ISIS), the issue of domestic radicalisation has taken on renewed significance for Western democracies. In particular, attention has been drawn to the potency of ISIS engagement on social media platforms like Twitter and Facebook. Several governments have emphasised the importance of online programs aimed at undermining ISIS recruitment, including the use of state-run accounts on a variety of social media platforms to respond directly to ISIS messaging. This article assesses the viability of online counter-radicalisation by examining the effectiveness of similar programs at the US State Department over the last decade. The article argues that governments attempting to counter online radicalisation of their domestic populations must take seriously the significant shortcomings of these State Department programs. The most relevant issue in this regard is the recurring problem of credibility, when the authenticity of government information is undercut by the realities of foreign policy practice, and existing perceptions of hypocrisy and duplicity are reinforced in target audiences.