Ethereum co-founder Vitalik Buterin has called for stronger safeguards to ensure the network’s neutrality, warning that overreliance on a handful of block builders could expose the blockchain to censorship.
In an August 22 post on X, Buterin outlined three strategies to reduce centralization risks: strengthening the public mempool, building distributed block-construction systems, and introducing fallback channels for transaction inclusion. Central to his vision is a new proposal known as Fork-Choice Enforced Inclusion Lists (FOCIL).
FOCIL would assign multiple proposers to each block slot, with one lead proposer setting transaction order and 16 auxiliary proposers ensuring that chosen transactions cannot be excluded. The design, Buterin argued, would prevent block builder oligopolies from gaining veto power while also extending to smart contract wallets and privacy protocols.
Buterin said the goal is simple: “to stop a small group of validators from deciding which transactions make it on-chain.”
Pushback From Developers
Not all in the Ethereum community agree. Developer Ameen Soleimani warned that FOCIL could create serious legal exposure, particularly for validators operating under U.S. jurisdiction. He pointed to the Tornado Cash case, where most validators avoided sanctioned transactions but still allowed eventual settlement — a compromise that balanced compliance with inclusion.
FOCIL, Soleimani argued, would eliminate that middle ground by forcing validators to include flagged transactions, potentially leaving them open to prosecution. He cautioned that regulators might see little distinction between proposers, attesters, or auxiliary participants, making all liable.
Beyond legal risks, Soleimani also questioned FOCIL’s viability, noting that it relies on validator “altruism” without providing incentives or protections. Without clear safeguards, he warned, the system could prove unsustainable.
The debate highlights a growing tension for Ethereum: how to preserve neutrality and censorship resistance while navigating increasingly complex regulatory environments.
