Heh, if I was still in Sudan I'd assemble a bunch of addresses and taint all their block rewards lol On a more serious note, random bitcoiners can't be fined for spending "illegal addresses" which means Marathon will be taking all the regulatory burnt and fines.

They don't have to publicly announce it and it is not that hard to figure out.
If a centralized business such as a mining pool is operating inside a certain jurisdiction that demands a license then you can simply look at the terms in that license and know what that business is doing.

I doubt they will be able to obtain a proportion that high under their purview, but yeah never really know.

51% attacks would definitely have far more repercussions than simple censorship. Reorganizing and opting out blocks that they don't like probably won't sit well with most people, more so than censorship within their blocks. If they're smart, they would either choose another pool or just sell their ASICs right away.

Yes, censorship and yes.
Yes. If there ever comes a day where the entire network is under regulatory control (if I may add, IMO highly implausible), you can't mix your coins if it doesn't get confirmed in the first place.

The government can already monitor every transaction and link them to real people via blockchain analysis. This is about censorship, not just surveillance.

If they can censor bitcoin, they can censor almost all altcoins too. At least we have Monero.

Sure, until the government decide that every coin which has been conjoined or mixed is deemed "tainted". If only everyone used these services by default, then there would be no transactions they could mine at all and this wouldn't be an issue. The more people who take their privacy seriously, the better it is for all of us.

Because they lose their incentive to do so. If an attacker can control 51% of the hash rate of bitcoin and only mine "approved" transactions, bitcoin still exists, is still traded on exchanges, still has value, and the attacker can still sell their block rewards. If an attacker can control 51% of Monero's hash rate, their options are to mine every transaction or none since they cannot differentiate between "approved" and "tainted". If they only mine empty blocks, then Monero dies and has zero value. Not to say it can't be done, but there would be no profit in doing so.

There are other ways Monero could be censored though, such as people having to submit their KYC details to a miner to be allowed to submit their transactions, but no coin is safe from a big enough attacker.

So what does OFAC really do? They publish a list of bitcoin addresses ... Then, if your address is there, just stop using it. Use another address.

How often does OFAC update their list?

You really only get on that list if you reuse addresses. If you never reuse addresses or publicly give them out to everyone, then it will never get on that list.

This list really targets perhaps those addresses posted on forums or photos or something, where they can easily link it to someone's identity, such as public donation addresses.

If one has the ability to use bitcoin, then they can step up and upgrade and have the ability to set up some website that gives new addresses every time. Of course, blockchain analysis companies may still track them, but this makes it more difficult.

Don't publish a master public key ... or do? Imagine if some known entity decides to publish a massive list of bitcoin addresses known all of them would get included in such a black list.

Like how big is the current OFAC list right now? Here, pastebin, 1 million addresses ... can sweep any of them, but if you really want to donate, send a private message and we'll give you your own donation address to send to.

Yes, move them. It's still going to move right now. Even if OFAC controls a large percentage of the mining hashpower and tries to get your tx blocked, it will eventually move.

It will take some time for the new address to get blacklisted. During that time, you can move it again a few more hops, then probably send it to some exchange if needed, or traded, or mixed, or coinjoined, or gambled or whatever. Then you move it again.

Then again, if you are already a target, you have other problems to deal with but on technical level, yeah, I don't see how they can keep up, unless they have a system updated in real time and require their OFAC compliant miners to keep updated every 10 minutes. I think it will be a headache for them, all of them, whoever they are.

They are trying to force permissions on a permissionless system. They can't even keep up with just plain physical cold cash.

We also have taproot in the future. Good luck to them analyzer companies.

If the amount of bitcoin or value is small enough, depending on the entity involved, they can probably ignore it, like if it's just dust. For at least 1 BTC, I'd be willing to pay a higher than normal tx fee (but not that much higher, can just monitor mempools now, looks like currently 3 sats will get through today.)

I think that for now it's a potentially dangerous thing that we should keep an eye on, but it's also something that probably won't get particularly popular in the mining community. I don't fully trust agencies like OFAC because of course their decisions can be politically motivated and addresses can get on that list for dubious reasons. But I agree with those who say that miners in China aren't likely to be interested in complying with whatever the US authorities claim to be illegal, so the issue seems minor for now. That being said, China could totally introduce a similar thing and enforce it upon mining farms, so the risks can get very real very fast.

No single mining entity or pool is going to go above 51% hash rate, simply because the participants of that pool will just switch elsewhere, not unless the pool also controls the miners themselves.

In theory, a single entity can just have a bunch of different "accounts" or "pools", and one pool might have 25% and another has 26%, they will just be under different names, but that kind of pool won't care about OFAC.

Before it becomes an issue, you'll see the other miners go ahead and do something and most likely most won't care about MARA as they can just build on top of whatever "clean" block they mine.

Like someone else said, just mine an empty block, it will be clean. But the miner won't get an tx fees from the clean block, just the base reward, which may be enough for now, but not in the distant future when plenty of tx will reward more than the base reward.

Pools are actually "centralized" because ... that's how pools work.. There are some "decentralized" pools I think, something p2p pool or what. I've not kept updated. The whole reason for pools to exist is because no single miner has enough hashpower to consistently mine blocks. One would need a relatively large percentage to "solo mine".

In this case, I believe MARA is their own miner, so maybe it can be an issue if they get too big. However, I think they won't get very far. Who knows ... they begin accepting other miners to the pool starting June, so we'll see what happens then.