We start by introducing the idea of echo chambers. Echo chambers are social and epistemic structures in which opinions, leanings, or beliefs about certain topics are amplified and reinforced due to repeated interactions within a closed system; that is, within a system that has a rather homogeneous sample of sources or people, which all share the same attitudes towards the topics in question. Echo chambers are a particularly dangerous phenomena because they prevent the critical assessment of sources and contents, thus leading the people living within them to deliberately ignore or exclude opposing views. In the second part of this paper, we argue that the reason for the appearance of echo chambers lies in the adoption of what we call 'episte...