In 2018, the United States Treasury named Bitcoin addresses on a sanctions list for the first time.
Nothing was seized. Nothing was banned. A list was published, and the list had addresses on it, and every institution that wanted to stay on the right side of American law now had a reason to look at those addresses and treat anything touching them as radioactive.
That is the whole mechanism. It needs a list, an address, and an intermediary with something to lose. No police, no court order against you personally, no proof that you did anything. Just a list, and a financial system that would rather not find out whether your coins are on it.
This chapter is about that machine, and about what happens to money that it cannot get hold of.
The machine has three steps Refusing a coin requires three things, in order, and each one depends on data that the ledger provides.
It gets listed. An address associated with something the authorities dislike is published. The address is the handle. Without it, there is nothing to publish.
It gets frozen. Institutions that hold customer funds are obliged to check deposits against the list and freeze anything that matches. The freeze is not a punishment of the sender; it is the institution protecting itself.
It gets skipped. A miner choosing which transactions to include can decline the ones that reference listed addresses. This is the step most people do not know exists, and it is the one that turns a banking policy into a network-level event.
T H E M AC H I N E O F R E F U S A L , A N D W H AT I T N E E D S TO R U N IT GETS LISTED IT GETS FROZEN IT GETS SKIPPED Bitcoin Addresses are public Deposits match a list Pools have filtered Epic Cash No addresses exist Nothing to match Nothing to select Each step needs the one thing a private ledger withholds: the identity of the coins.
Remove any one of the three and the machine stops. And all three depend on the same precondition: visibility. To list an address, you must be able to see addresses. To freeze a deposit, you must be able to match it. To skip a payment, you must be able to tell one payment from another.
Bitcoin provides visibility by design, which is why all three steps have been exercised on it.
The record on Bitcoin It is worth being precise, because "Bitcoin can be censored" is usually said as a slogan and the specifics are more interesting.
In May 2021, Marathon mined block 682,170 and deliberately left out transactions associated with sanctioned addresses. The policy was reversed four weeks later after public backlash.
In October 2023, F2Pool — the pool behind roughly fourteen percent of blocks at the time — skipped sanctioned payments. Its co-founder confirmed the filter publicly. In December 2024, nine F2Pool blocks left out sanctioned payments again; other pools mined them later.
None of those payments was destroyed. They were delayed, sometimes for hours, by a private company making a policy decision about which valid transactions it would include.
The structural facts make this easier than it should be. Three pools have mined a majority of all blocks in recent measurements. Around forty percent of hashrate has run through AntPool and its proxies. More than eighty percent of mining chips have come from a single manufacturer.
And a filter doesn't need the whole network — it needs enough pools to matter, which is a much smaller number.
What Epic changes is not the miners' behavior, it's their information Here is the part that is easy to miss. Epic does not ask miners to be virtuous. Miners on any chain can decline to include a transaction; that is what mining is, and no design removes it.
What Epic removes is the ability to know which transaction to decline.
Nothing to list. There are no addresses in the ledger. When a payment is constructed, the output is a one-time object with no link to a person, an account, or a previous output. There is no handle to publish.
Nothing to flag. Amounts are hidden behind commitments, and spent outputs are cut away, so there is no provenance to grade, and nothing on the chain to look up or hand to an analysis firm. Linking some payments is possible only through costly, targeted surveillance of the network itself.
Nothing to skip. A miner can verify that a block balances and that the signatures are valid. It cannot see who sent what to whom, which means a miner asked to exclude certain coins would have to exclude everything or nothing. Selective censorship requires selection, and selection requires visibility.
This is what the one-page essay means by the line "unstoppable is a claim, fungible is a design." No network can promise that a hostile government will not try. What a design can do is make the attempt require the one thing a privacy chain withholds: the identity of the coins.
Better than cash, in one specific way Physical cash is the closest thing most people have to fungible money, and it is not perfectly fungible either.
Banknotes carry serial numbers. A note used in a robbery can be recorded, and a note recorded can be watched for. Banks and retailers mark notes, check them, and occasionally refuse them. In countries with capital controls, the physical form is the first thing controlled, because it is the easiest to count at a border.
Epic's position is that a coin should carry no serial number at all — not a hidden one, not an encrypted one, but none, because the output that would carry it is deleted when it is spent.
That is a stronger claim than cash makes, and it is the precise reason the word "fungible" belongs in the design section of this book rather than the marketing section.
What fungibility does not protect you from This is where honesty costs something, so it is worth paying in full.
Fungibility makes coins interchangeable. It does not make you invisible to the institutions you choose to deal with.
An exchange can still refuse your deposit. It can require identification, decline your jurisdiction, close your account, or decide your transaction pattern looks wrong. It simply cannot do those things on the basis of where your coins have been, because it cannot see where they have been. The refusal becomes about you rather than about the coin — which is a meaningful improvement, and not the same as immunity.
A government can still ban the exchange, block the website, or make it illegal to hold the asset. It cannot blacklist your coins, because there is no list that would work.
And a miner can still leave your transaction out of a block for any reason it likes, including no reason at all. It just cannot do so selectively across a category of coins, because it cannot tell which coins are which.
So the accurate claim is narrower and stronger than "uncensorable." Epic removes the coin-level handle that censorship needs. It does not remove the human one.
Why this cannot be added later The tempting conclusion is that any chain could adopt this if it wanted to. It cannot, and the reason is structural rather than political.
Fungibility requires that the ledger contain no history. A chain that has been transparent for a decade has a decade of history that cannot be un-recorded — every address, every amount, every link, permanently public and permanently copyable. You can add a private mode on top, and you will still have the old data underneath, and a coin that moves from the private mode into the transparent one becomes traceable again at the boundary.
You cannot retrofit the absence of a record. You can only build a chain that never made one.
That is the argument for starting over rather than upgrading, and it is the argument this book has been building since chapter four. Epic launched in 2019 with no addresses and no amounts in the first block. There is no earlier version of it with a transparent history, because there is no earlier version.
What this is worth Put the two halves together and the design claim becomes concrete.
Bitcoin can be filtered because every payment is visible, and it has been filtered, by named pools, in named blocks, on the public record. Epic cannot be filtered in the same way because the information the filter requires does not exist — not concealed, not encrypted, absent.
Whether that matters to you depends on what you think the next decade looks like. If you believe financial systems will remain open, permissionless and neutral toward holders of privacy coins, the property is a nicety. If you think sanctions lists will keep growing, that exchanges will keep tightening, and that "where did these coins come from" will become a standard question at every on-ramp, it is the whole game.
The book is not going to pretend the first view is unreasonable. It is going to point out that the second view requires no prediction at all — it is a description of the direction of travel since 2018.
Next: the money itself. Supply, emission, and the uncomfortable arithmetic of a coin that is already mostly mined.