Main Points:
- Bitcoin inscriptions, used to embed images and arbitrary data, have surged, threatening blockchain bloat and deviating from Bitcoin’s monetary focus.
- Pseudonymous developer GrassFedBitcoin proposed pull request #28408 to enable node operators to filter inscriptions by default.
- Economist and The Bitcoin Standard author Saifedean Ammous pledged “a few sats” to fund a full-time developer for spam mitigation efforts.
- Blockstream CEO Adam Back criticized inscription filtering as an endless “arms race.”
- Community voices debate whether fighting inscriptions equates to censorship or necessary protocol preservation.
- Mempool Research warns widespread inscription adoption could inflate average block sizes from ~1.5 MB to as much as 4 MB.
- Emerging trends—like BRC-20 tokens and security vulnerabilities (e.g., pinning attacks)—underscore the need for robust countermeasures.
1. Background: The Rise of Bitcoin Inscriptions
Since the Taproot upgrade in November 2021, Bitcoin’s OP_RETURN opcode has enabled developers to inscribe arbitrary data—ranging from simple text to high-resolution JPEGs—directly onto satoshis, giving rise to the so-called “inscriptions” or Ordinals protocol. This functionality has catalyzed a vibrant ecosystem of on-chain NFTs, BRC-20 tokens, and meme assets. However, inscriptions have also accelerated the growth of Bitcoin’s blockchain, driving average block sizes up from roughly 1.5 MB to peaks above 2 MB and fueling debates about scalability and network purpose.
Critics argue that embedding large media files on a payment-focused ledger is tantamount to digital graffiti, burdening node operators and end-users with increased storage and bandwidth requirements. Proponents counter that inscriptions unlock novel use cases, expand Bitcoin’s utility, and attract fresh user engagement. This tension between innovation and preservation frames the current debate over inscription filtering.
2. GrassFedBitcoin’s Proposal: Merging PR#28408
In mid-May 2025, the pseudonymous developer GrassFedBitcoin reignited the discussion by calling for Bitcoin Core maintainers to merge pull request #28408. The proposal would introduce a configurable, default policy within Bitcoin Core nodes to suppress or reject inscription transactions that exceed a defined data threshold. GrassFedBitcoin argued that past relaxations of OP_RETURN limits were based on “false assumptions” that they would not lead to significant blockchain bloat, and maintained that “no one running a node wants to relay inscriptions”.
By empowering node operators with built-in filtering tools, the PR aims to reduce unnecessary on-chain congestion, preserve Bitcoin’s role as a sound monetary protocol, and discourage misuse of limited block space. Yet, implementers worry this could fracture consensus if adoption is uneven, potentially leading to network forks or degraded user experience for those unwilling to run custom filter settings.
3. Saifedean Ammous’s Funding Pledge
Renowned economist and author Saifedean Ammous—best known for The Bitcoin Standard—publicly endorsed the inscription-filtering initiative, stating he would “throw in a few sats” to support a dedicated developer focused on raising the cost and difficulty of sending spam inscriptions. Drawing an analogy to email spam, Ammous emphasized that while eliminating spam entirely may be impossible, accelerating the financial ruin of spammers is a worthwhile endeavor.
Ammous clarified that fighting spam is not equivalent to censorship, highlighting that full node operators already exercise discretion in rejecting non-standard or invalid transactions by policy:
“Fighting spam is not censorship—node runners rejecting spam are as valid as the spammers themselves.”.
His commitment to contribute financially reflects growing alarm within segments of the Bitcoin community regarding the network’s evolving use cases and cost structure.
4. Counterpoint: Adam Back’s “Arms Race” Critique
In stark contrast, Blockstream CEO Adam Back dismissed inscription filtering as a quixotic “arms race.” He argued that as soon as one filtering rule is deployed, spammers can obfuscate payloads through novel encoding techniques, forcing constant updates to filter definitions—a cycle that ultimately arms neither side.
Back’s position warns that protocol-level filtering may engender a maintenance burden disproportionate to its benefits, and that open-ended data embedding will persist so long as miners accept higher-fee transactions containing inscriptions. He urged skepticism of solutions that rely on heuristic or signature-based filtering, suggesting instead that economic disincentives (i.e., higher network fees) naturally regulate non-financial traffic.
5. Community Responses and Broader Debate
The Twitter (X) thread sparked diverse reactions: some community members sarcastically labeled inscription tool developers at certain startups as “unwilling QA engineers,” advocating for their methods to be entirely unstandardized. Others pressed Ammous to go further—proposing that spam-tool maintainers be “deprecated” or overloaded with counter-infrastructure, effectively weaponizing engineering resources against themselves.
Meanwhile, a faction of purists—recalling the original “block size wars” of 2015–2017—warns that ceding ground on censorship principles sets a dangerous precedent. They champion a minimalist vision wherein Bitcoin remains a lean settlement layer, and any non-monetary data is strictly off-chain via layer-2 networks.
6. Technical and Scalability Impact
A February 4 report by Mempool Research projects that, under scenarios of widespread inscription adoption, average block sizes could balloon from ~1.5 MB today to as much as 4 MB per block—nearly tripling the data footprint of each new block. At that rate, if unchecked, the Bitcoin blockchain might exceed 1 TB of total data as early as late 2026 (with more conservative estimates placing 1 TB growth between 2027 and 2029).
Rising block sizes exacerbate storage, synchronization, and bandwidth costs for full node operators, potentially reducing decentralization as fewer participants can shoulder the resource demands. Layer-2 solutions—such as the Lightning Network—offer partial relief by settling transactions off-chain, but inscriptions bypass layer-2 entirely, embedding themselves at the base layer and sidestepping off-chain venues.
7. Emerging Trends: BRC-20 Tokens and Security Concerns
Beyond simple media inscriptions, the BRC-20 token standard—leveraging JSON-based inscriptions—has enabled fungible token issuance on Bitcoin, spawning meme coins like ORDI with market caps exceeding $1 billion. However, novel research has uncovered security vulnerabilities, such as the “BRC20 pinning attack,” wherein adversaries trickle lower-fee inscription transactions into the mempool to lock user transfers and disrupt liquidity—a flaw demonstrated against Binance’s ORDI hot wallet, temporarily suspending withdrawals for hours.
These developments underscore that inscription ecosystems—once viewed as benign creative outlets—carry financial and security risks that may demand more rigorous protocol-level guardrails.
8. Future Outlook and Alternative Solutions
As inscription debates intensify, various technical proposals have emerged alongside PR#28408:
- Economic Disincentives: Gradually raising minimum relay fees or implementing dynamic fee markets to price out low-value inscription traffic.
- Enhanced Mempool Policies: Allowing nodes to prioritize known wallet-related or Lightning channel openings over opaque inscription transactions.
- Smart Data Commitments: Shifting large-file storage to dedicated decentralized data networks and reserving base layer for succinct merkle proofs.
- Consensus-Level Soft Forks: Proposals to tighten or re-define OP_RETURN data limits at the protocol layer, though these face uphill political and technical challenges.
Some developers advocate migrating inscription innovation to sidechains or stateless rollups—similar to how Ethereum uses data blobs—thereby preserving Bitcoin’s lean core while accommodating data-rich use cases elsewhere.
Conclusion
The eruption of inscriptions on Bitcoin spotlights a fundamental crossroads: should the network evolve into a general-purpose data layer, or should it double down on minimalism, preserving storage and consensus integrity? The push by GrassFedBitcoin and the funding pledge from Saifedean Ammous illuminate a growing faction prioritizing protocol purity and scalability. Conversely, Adam Back’s cautionary “arms race” framing reminds us of the complexities inherent in policing a permissionless network.
Ultimately, the path forward may rest on a blend of economic disincentives, community norms, and selective protocol adjustments—striving to balance innovation with the bedrock principle of a decentralized, efficient monetary network. As Bitcoin continues to mature, the debate over inscriptions, filtering, and fundamental purpose will shape its trajectory for years to come.
