As traditional social media fragments into smaller platforms and communities, researchers warn that decentralization could make moderation harder and extremism easier to organize. The shift from monolithic platforms to a scattered landscape creates both opportunities and serious risks - and we're not prepared for either.The era of Facebook and Twitter dominating online discourse is ending, not with a bang but with a slow fragmentation. Users are migrating to Mastodon, Bluesky, Discord servers, and countless niche platforms. That sounds like a win for decentralization and user control. But it also means we're starting over on problems we spent a decade learning to manage.Content moderation at scale is hard. Facebook employs thousands of moderators and spent billions on AI systems to detect harmful content. Those systems are imperfect, but they exist. Now imagine trying to replicate that effort across a hundred smaller platforms, each with different resources, policies, and technical capabilities. Most of them can't and won't.The research cited in recent analyses suggests that decentralization creates opportunities for bad actors to find poorly-moderated spaces and use them as organizing platforms. When extremist content gets banned from one platform, those users don't disappear - they migrate to places with weaker moderation. The fragmented landscape makes it easier to find a safe haven.There's also the problem of echo chambers becoming more extreme. On large platforms, you're at least exposed to diverse viewpoints, even if you don't engage with them. On niche platforms built around specific communities or ideologies, that exposure disappears. The risk is that decentralization leads to radicalization by isolation.This doesn't mean decentralization is bad. The concentration of power in a few massive platforms created its own set of problems. But we need to be honest about the tradeoffs. Moving from a few giant platforms to many small ones doesn't automatically make online spaces healthier. It just creates different problems.What's needed is infrastructure for decentralized moderation - tools and standards that smaller platforms can use without requiring massive teams and budgets. Some of this work is happening through projects building shared blocklists and federated moderation systems. But it's early, and the problems are moving faster than the solutions.The optimistic take is that we're in a transition period, and better tools will emerge. The pessimistic take is that we're creating a hundred different places for toxicity to flourish, each too small to police effectively but collectively doing enormous harm. Both could be true.We spent a decade learning to moderate Facebook. Now we're starting over with a hundred smaller platforms, each with different rules and capabilities. The question is whether we can avoid creating a hundred different places for bad actors to organize.