ABSTRACT This paper addresses the ways new entrants and mobile technologies have become significant challenges to the old news’ legitimacy models by focusing on pseudo-professional WhatsApp news groups from a journalistic authority standpoint. Based on a comparative textual analysis of how a breaking news event was handled by a leading Israeli pseudo-professional WhatsApp news group, compared to how it was covered by the Israeli News13 TV news broadcast, the findings indicate how, by adopting professional news practices and establishing unique relations of information exchange with traditional news outlets, journalistic authority is challenged by pseudo-professional WhatsApp news groups in today’s mobile news environment.