Conspiracy theories proliferate online. We provide an overview of information consumption patterns related to conspiracy content on four mainstream social media platforms (Facebook, Twitter, YouTube, and Reddit), with a focus on niche ones. Opinion polarisation and echo chambers appear as pivotal elements of communication around conspiracy theories. A relevant role may also be played by the content moderation policies enforced by each social media platform. Banning contents or users from a social media could lead to a level of user segregation that goes beyond echo chambers and reaches the entire social media space, up to the formation of ‘echo platforms’. The insurgence of echo platforms is a new online phenomenon that needs to be investigated as it could foster many dangerous phenomena that we observe online, including the spreading of conspiracy theories.

阴谋论在网上泛滥。我们概述了四个主流社交媒体平台（Facebook、Twitter、YouTube 和 Reddit）上与阴谋内容相关的信息消费模式，重点关注小众平台。意见极化和回声室似乎是围绕阴谋论进行交流的关键要素。每个社交媒体平台实施的内容审核政策也可以发挥相关作用。禁止社交媒体中的内容或用户可能会导致一定程度的用户隔离，超出回声室并触及整个社交媒体空间，直至形成“回声平台”。回声平台的兴起是一种新的在线现象，需要进行调查，因为它可能会助长我们在网上观察到的许多危险现象，