This article aims to understand the challenges involved in assigning information literacy meaning in classroom practices of teaching and assessing both credibility evaluations in particular and information literacy generally. A qualitative study has been conducted in two Swedish upper secondary school classes with pupils in the Social Science Programme’s school year 11. The study provides an inside view on the challenges that educators meet in contemporary schools in a changing media landscape, which, to an increasing degree, invites ordinary users to become producers of information and its organisation. Various ways of making information literacy in general, and critical evaluation of sources in particular, into an object of teaching are discussed, and an influential discourse in relation to credibility is identified, which is a discourse of control. The study concludes that educators need to revisit traditional criteria for the critical evaluation of sources in order to gain increased reflexivity when it comes to evaluating the credibility of sources.