Jimmy Song, a prominent Bitcoin developer and advocate, has voiced strong opposition to the imminent decision by Bitcoin Core developers to eliminate the OP_Return limit for non-monetary data embedded in the Bitcoin blockchain during the upcoming Bitcoin Core 30 upgrade. He criticized this move, referring to it as embodying a “fiat” mentality that runs counter to the spirit of Bitcoin.
Song accused the Core developers of dismissing concerns raised by users regarding the removal of the current 80-byte OP_Return limit. He highlighted the growing dissent within the Bitcoin community, specifically pointing to the backlash from node runners who believe this change undermines the protocol’s foundational principles. “The idea that spam is difficult to define, and because of this ambiguity, we shouldn’t be making any distinctions at all in the software, is a time-wasting argument from fiat politics,” he stated. “The non-monetary uses of Bitcoin are spam. You can argue whether that’s something desirable or not, but saying you can’t define it is a stalling tactic meant to avoid the real argument about actual impact—particularly, the long-term impact of this change.”
The pull request to remove the OP_Return limit has not only provoked significant backlash but has also been categorized as highly unpopular among the community, yet has been pushed through nonetheless. The ongoing OP_Return debate, which has persisted for nearly six months, brings to mind the notorious Bitcoin block size wars between 2015 and 2017. Those conflicts ultimately resulted in a hard fork that produced Bitcoin Cash (BCH), prompting speculations among some community members that the current OP_Return disputes might lead to a similar schism.
Amidst this controversy, the fallout from the decision has led to a pronounced increase in the number of Bitcoin node runners migrating towards Bitcoin Knots, an alternative implementation of Bitcoin node software. This transition has been notable; Bitcoin Knots now accounts for approximately 20% of the network—a stark rise from about 1% in 2024—illustrating a significant shift in user allegiance within just nine months.
Bitcoin Knots allows node operators to enforce stricter data size limits, which advocates argue is essential for maintaining the decentralization that Bitcoin espouses. Since Bitcoin’s inception in 2009, the ledger has accumulated around 680 gigabytes of data, a volume made manageable by its simple architecture and strict data limits. This low storage requirement means that individuals can run a Bitcoin node on standard retail hardware for as little as $300, fostering broader access and maximizing decentralization.
In contrast, other blockchain networks with higher throughput and smart contract capabilities often generate significantly more data, necessitating specialized commercial hardware that can cost tens of thousands of dollars to operate. This disparity effectively restricts node operation to affluent investors and large enterprises, raising concerns about centralization and the potential for collusion among a limited number of nodes to manipulate consensus rules or reverse transactions.
The ongoing debates and subsequent shifts indicate the volatility and complexity that continues to characterize the Bitcoin ecosystem as it evolves.