Digital platforms are under public scrutiny and face a negotiation process regarding their social responsibility. In this institutional discourse about moral responsibilities, corporate actors aim at defending the legitimacy of digital platforms. This study conceptualizes strategic communication as a means for conveying conformity to legitimacy expectations, to shape legitimacy judgements, and to discursively conduct institutional work. A critical discourse analysis of Zuckerberg’s testimony before the EU Parliament finds that prag-matic, moral, and cognitive legitimacy is signaled through corporate ability, responsibility, and conformity narratives, respectively. Moreover, Zuckerberg’s techno-libertarian talk advocates Silicon Valley ideology through utility narratives of artificial intelligence. Thus, Zuckerberg conducts institutional work as an institutional entrepreneur whose strategic communication seeks to manipulate views as well as institutions.