If you’ve been in Bitcoin for more than a minute, you’ve probably heard people compare today’s “Spam Wars” to the infamous Blocksize Wars almost a decade ago.
The energy, the vitriol, the tribalism; it’s all back in force, only this time, instead of arguing over block sizes, the battlefield is OP_RETURN and the growing divide between Bitcoin Core and Knots.
How the Spam Wars Began
The roots of the Spam Wars date back to 2023. That’s when Ordinals burst onto the scene. They enabled anyone to embed digital art, NFTs, and other types of data right onto Bitcoin’s blockchain.
Many heralded Ordinals for unleashing all kinds of innovations on Bitcoin. Some foresaw the problem of spam and bloat on the chain driving up transaction fees for everyday users.
In early 2025, the Spam Wars moved up another gear. Bitcoin Core developers unveiled plans to scrap the 80-byte OP_RETURN limit in their upcoming v30 release.
They were hoping to make Bitcoin more versatile for new kinds of on-chain activity. To many on the Core side, as long as transaction fees are paid, any use of Bitcoin is fair game.
But not everyone shares that vision. Luke Dashjr, long-time Bitcoin developer and lead maintainer of Bitcoin Knots, sees the shift less as open experimentation and more as a massive red flag.
To him, lifting the limits is an open invitation for spam, which would turn Bitcoin into a data dumpster for non-financial junk and threaten its role as money.
Knots is quickly becoming the rallying point for critics who believe Core is surrendering Bitcoin’s neutrality, and as tensions rise, more node operators are starting to flock over: Knots’ share of the network has hit 18.5%.
What’s Really at Stake
At its heart, the Spam Wars are not about one line of code or a technical tweak. They’re about philosophy.
Is Bitcoin supposed to remain a pure monetary settlement layer, laser-focused on censorship resistance and decentralization?
Or should it embrace a wider role, serving as a canvas for experiments, art, and data, so long as users pay the costs?
Bitcoin Core’s side argues for maximum freedom. As Core developer and Libertarian Jameson Lopp posted:
“I truly detest politics. Thus I have little patience for those who try to impose traditional governance models onto Bitcoin. If you don’t like anarchy, you’re free to leave.”
Knots’ side argues that without rules to preserve Bitcoin’s monetary function, the network risks bloat and centralization. Luke Dashjr has warned:
“What do you think will happen now that Core is opening the floodgates to spam, and essentially endorsing it?… Any chance we have of making Bitcoin a success will go out the window.”
And it’s not just Luke waving the warning flag. Samson Mow, former CSO at Blockstream and founder of Jan3, has also taken Knots’ side.
He issues a warning that allowing unbounded spam is a slippery slope that could erode Bitcoin’s resilience as a store of value.
A Serious Risk to Bitcoin?
The longer the Spam Wars drag on, the louder the voices are getting, and not all of them are aligned neatly with one camp.
Adam Back, CEO of Blockstream and a long-time Core supporter, broke ranks in tone if not substance on Friday. He cautioned that dismissing spam risk outright was the wrong move. He wrote:
“Bitcoin is about money; spam has no place in the timechain.”
Back’s comments are notable not just because of his standing but also because they hint at what’s being missed.
This isn’t just about two codebases in a vacuum but about the global perception of Bitcoin’s neutrality and purpose.
Peter Todd, another long-standing Core-aligned developer, struck an even harsher tone on Saturday, placing the blame not on Core but on Knots supporters for escalating tensions:
“This has gotten so out of hand that the Knots crowd are becoming a serious risk to Bitcoin. We can’t stop people from putting illicit data in the Bitcoin chain. We just can’t.”
Where It Goes From Here
October 2025 looms large, with Bitcoin Core’s v30 release scheduled to roll out the OP_RETURN change.
How miners, node operators, and exchanges react will determine whether this remains a loud but contained civil war or tips into another chain-splitting crisis reminiscent of 2017.
The Spam Wars are no longer a niche developer squabble. With big voices weighing in, rising tribalism, and the October deadline ticking closer each day, Bitcoin may soon face its biggest ideological test since the Blocksize Wars.