Do Platform Migrations Compromise Content Moderation? Evidence from r/The_Donald and r/Incels

TL;DR

This study examines how community bans on Reddit influence the growth, toxicity, and radicalization of affected communities on their new platforms, revealing both activity reduction and increased toxicity in some cases.

Contribution

It provides large-scale empirical evidence on the effects of community-level moderation, highlighting nuanced outcomes including decreased activity and increased toxicity post-migration.

Findings

Moderation significantly reduces activity on new platforms.

r/The_Donald users show increased toxicity and radicalization signals.

Community migration can lead to more toxic and radical communities despite lower activity.

Abstract

When toxic online communities on mainstream platforms face moderation measures, such as bans, they may migrate to other platforms with laxer policies or set up their own dedicated websites. Previous work suggests that within mainstream platforms, community-level moderation is effective in mitigating the harm caused by the moderated communities. It is, however, unclear whether these results also hold when considering the broader Web ecosystem. Do toxic communities continue to grow in terms of their user base and activity on the new platforms? Do their members become more toxic and ideologically radicalized? In this paper, we report the results of a large-scale observational study of how problematic online communities progress following community-level moderation measures. We analyze data from r/The_Donald and r/Incels, two communities that were banned from Reddit and subsequently migrated to their own standalone websites. Our results suggest that, in both cases, moderation measures significantly decreased posting activity on the new platform, reducing the number of posts, active users, and newcomers. In spite of that, users in one of the studied communities (r/The_Donald) showed increases in signals associated with toxicity and radicalization, which justifies concerns that the reduction in activity may come at the expense of a more toxic and radical community. Overall, our results paint a nuanced portrait of the consequences of community-level moderation and can inform their design and deployment.