First-order effects

• Instance admins must immediately choose whether to block or continue federating with Gab's servers, since defederation is the only enforcement tool the protocol gives them.
• Mastodon's existing users face the moderation outcomes directly — their feeds either absorb Gab content or fragment further as admins cut federation ties.

Second-order effects

• Volunteer admins inherit the compliance and liability work that a centralized platform would handle, a burden heavy enough that institutional players like FT Alphaville later concluded running a server was not worth it.
• The fediverse's public reputation becomes coupled to its least-moderated instances, pressuring Mastodon's project leadership to formalize guidance — the path that led to Rochko publicly defending the moderation model and the project moving toward nonprofit governance.

Third-order effects

• If decentralized networks keep growing, moderation by contestable gatekeeping — individual admins deciding who to federate with — becomes the industry's alternative template to platform-wide content policy, with each high-profile bad actor like Gab testing whether it holds.
• The pattern points toward a structural split in social media between centrally moderated platforms and federated ones whose safety depends on admin coordination, shaping which institutions are willing to host communities at all.