The proliferation of radical online communities and their violent offshoots
has sparked great societal concern. However, the current practice of banning
such communities from mainstream platforms has unintended consequences: (I) the
further radicalization of their members in fringe platforms where they migrate;
and (ii) the spillover of harmful content from fringe back onto mainstream
platforms. Here, in a large observational study on two banned subreddits,
r/The\_Donald and r/fatpeoplehate, we examine how factors associated with the
RECRO radicalization framework relate to users' migration decisions.
Specifically, we quantify how these factors affect users' decisions to post on
fringe platforms and, for those who do, whether they continue posting on the
mainstream platform. Our results show that individual-level factors, those
relating to the behavior of users, are associated with the decision to post on
the fringe platform. Whereas social-level factors, users' connection with the
radical community, only affect the propensity to be coactive on both platforms.
Overall, our findings pave the way for evidence-based moderation policies, as
the decisions to migrate and remain coactive amplify unintended consequences of
community bans.

本研究的大型观察研究基于两个被禁止的 subreddits，r/The_Donald 和 r/fatpeoplehate，探究关于在线激进化的因素，特别是这些因素如何影响用户迁移到边缘平台的决策，以及那些在边缘平台发帖的用户是否会继续在主流平台上发帖。研究结果表明，个人层面的因素与发帖在边缘平台的决策有关，而用户与激进社区的联系这一社会层面的因素仅影响在两个平台上同时进行的倾向性。总的来说，我们的结果为循证管理政策铺平了道路，因为迁移和同时活跃的决策进一步恶化了社区禁令的意外后果。