Adam Back warns BIP-110 UASF could split BTC

Blockstream CEO Adam Back criticized BIP-110 on June 8, saying the proposal is technically flawed and lacks broad ecosystem backing. He warned that forcing the change through a user-activated soft fork could produce a minority Bitcoin chain rather than a network-wide upgrade.

BIP-110 would limit non-monetary data embedded in Bitcoin transactions. Its authors propose a user-activated soft fork (UASF) that lets node operators and users enforce new rules even if miners do not signal support. Back and other critics say that method risks creating two incompatible rule sets if miners and major service providers do not follow the change.

Back contrasted BIP-110 with the 2017 SegWit activation, noting that SegWit followed years of coordination among developers, miners and node operators. He wrote: “the reason it doesn’t have consensus is it’s stupid idea, doesn’t work, and completely fails at technical consensus.” Back added that forcing the proposal without wide agreement would lead to a minority contentious fork, not a legitimate upgrade.

Proponents of BIP-110 argue the proposal would reduce blockchain spam by restricting non-monetary uses of the ledger. Supporters have pointed to user-driven activation as a path to change. Back rejected that comparison and posted an image captioned “the 110 contentious fork in a nutshell” to illustrate his view that the proposal would create a boundary not recognized by the wider consensus process.

Investor Michael Saylor also described BIP-110 as a protocol risk, calling it “Bitcoin’s biggest self-inflicted risk.” Node-level support for the proposal remains in the low single digits, and the activation window in the coming months narrows the time available for debate and testing.

Opponents of BIP-110 say the proposal’s technical design and activation method create the risk that two incompatible chains could emerge, potentially splitting users, market liquidity and economic activity. Back noted that durable upgrades require both technical correctness and broad buy-in from developers, miners, exchanges and node operators.

Back maintained a bullish investment stance on Bitcoin amid the dispute. On June 9 he referred to “the bitcoin permabulls” when discussing long-term market sentiment, and emphasized that his approach to Bitcoin investment rests on long-term sound money principles.

The BIP-110 debate will continue as node operators, exchanges and development teams review technical audits and set policy positions. The proposal’s authors and critics are set to press their cases in the weeks before the activation window closes.