This Might Sounds Strange: Bitcoin Violates the Principle of Money Fungibility

[VirosaGITS]

If the time comes that certain coins are considered permanently clean and others permanently dirty in a future regulated world system,
the community as a whole should purposefully contaminate all clean coins found on the blockchain.

And what incentive does anyone have in doing that? Should we use the Bitcoin Honor System(TM) and hope people are willing to devalue their clean money?

I have a better idea. Fungibility.

I see a pattern happening here:

1. Issues raised with Bitcoin's fungibility get brought to light

2. Supporters of bitcoin's "fungibility" propose solution X

3. Those who want to see reality for what it is go on to debunk solution X given it is a patch to the system and not an actualy addition to bitcoin's protocol which attempts to fix bitcoin's fungibility issues in a ROUND-ABOUT-WAY.

4. repeat step 2 for solution X+1 until X+n is reached

5. agree to disagree


There are so many supposed solutions to fixing bitcoin's fungibility problem but they don't hit the issue head on. It is always some sort of of chain (outside of bitocin protocol) PATCH which does not fix anything deterministically 100%.

Fungibility isint a problem in the first place. Its not because a dead man said it need to be fungible than the principle still hold true. I very much doubt he could foresee hundreds of years in the future that money would become digital and ethereal.

Now we're in the era of Security.

So in the future if you took your bitcoins to all bitcoin merchants to spend them or exchange them and you are denied doing so because of your coins being tainted that's not a problem?

I would see it as a problem.

Thats like saying all the shops in the world will stop accepting bills printed after a certain date, or refusing all bills that ever got some woman perfume on it. Its just not feasible. Most merchants that accept online transactions, FIAT AND BTC don't give a shit about USD or BTC, they get paid in the currency they want.

And payment processors that handle BTC live on BTC, so suiciding by refusing 90% of coins is not going to happen.

Wrong.

You are comparing a digital transparent decentralized ledger (virtual and globally accessible in an instant) to physical analogies of perfume and dates printed on piece of paper?

come on you can't compare the two as if they are equal ways to black list a currency from usage.

You can clearly see where bitcoins come from and go to ON THE BLOCK CHAIN
with the touch of a button and some software for parsing the block chain . <------ EFFICIENT

You can't clearly see your examples globally and instantly for blacklisting. <-----not EFFICIENT
^ Nor can you easily trace the exact/full history of each physical fiat bill efficiently.



90%? Where did you come up with that number? You don't know the exact mechanism for black listing to be put into place at some future date. There are probably 50 shades of black listing that will probably spring up at some point depending upon each government/regulatory department's discretion.

No, not wrong. Comparing it to fiat is just fine. You're using an idea, term and criteria that was built with no knowledge of how things could be in the future.

The point is, *you* are using a term used for criteria on previous kind money and *you* are applying it to Bitcoin. *You* are basing your perspective on dated concept that hold no value here.

And you. The 90% come from you. Even in the case 90% of merchants, and thats magnitude higher than it could happen in the worse case scenario. Then those going through that system would just collapse.

Payments processor pays merchants in the currency they want, if they stop accepting any non clean 0x coins, the BTC portion of their dealings would just die.

You're suggesting a problem based on fungibility when there is actually... None. Is there a problem with spending X vs Y bitcoin? No.

Will there be one? No.

So what i been saying in the few posts, if that wasn't clear enough, is that your whole perspective, your whole argument is based on a fallacy.

1. Fungibility is a concept used on money previous to bit coin - yes

2. Fungibility of fiat is different from bitcoin. Fiat fungibility is decreed by law (at least in the U.S.) bit coin fungibility is decreed by no CENTRAL authority/business/company. So the topic of fungibility is up to the marketplace and any laws/regulations that are enforced upon said businesses. Fungibility of precious metals such as gold and silver has its own take on it in its respective market place much like bitcoin. Only thing with precious metals you can't black list certain atoms of silver or gold.  

You can't tell where a paper dollar has been by looking at it. You can't tell its completely transactional history by looking at it. Nor can you tell where an atom of silver or gold has been and its transactional history from the day it was dug out of the earth. Their respective histories are hard to identify. Bitcoins on the block chain are easily identified.

3. You tried to equate all shops in the world stopping accepting bills with a particular date on them or perfume on them. THIS very comparison when used as an analogy of bitcoin blacklisting in reference to the concept of fungibility (every unit of account in a system is interchangeable and indistinguishable) is a flawed comparison as one is a physical form that cannot be efficiently executed (your example) and my example where a bitcoin business or government authority posts a digital list of addresses that are not to be accepted for commerce, which every person with an internet connection has access to, can be done efficiently.

The two scenarios are worlds apart in terms of the ability to execute such tasks separately.

4. You say that fungibility holds "no value" here? How is it not a valuable topic of discussion or concern when a bitcoin user (BOB) buys bitcoins from someone buy does not realize those coins were stolen from an exchange (via a hack/heist) now bob is being told his coins are not accepted at particular merchants and in some cases his coins could be confiscated if he deposits it to an exchange and they refuse to allow him to have it because "coins are blacklisted" by a government authority who regulates said business. <---- You see no value in fungibility here at all?

5. The 90% did not come from me. Please post a quote/link. I never mentioned 90% to my knowledge.

6. Bitpay just stopped accepting "tainted" bitcoins from their own black list not even a month ago.  LINK: https://www.reddit.com/r/Bitcoin/comments/3mea6b/bitpay_is_blacklisting_certain_bitcoins_rejecting/

7. Is there a problem? In my view yes there is. At the moment it isn't at the crux of everyone's attention like THA BLAWK SAIZE DEEHBATE but it will be if users start getting turned away from using/spending/exchanging their bitcoins because those coins have a history from a past theft/crime.

My argument is based on fact.

MTGOX refused to allow bitcoinica coins to go back to their depositors after bitcoinica was hacked. BTC-e disallowed withdraw/exchange of the coins from the evolution marketplace theft. Bitpay is black listing certain bitcoins and rejecting customers.

Fallacy? No.... fact! Get it straight.

As I said, right now the issue of fungibility is not a hot topic like other topics but it is a huge issue for users that want to have a currency that is fungible and allows them to have financial privacy. At some point I see the topic of bitcoin fungibility being in the bitcoin headlines more and more as time goes on. Time will tell if I am right.

You have not referenced any links/quotes/examples that prove my argument is flawed.

You still do not understand one word of what i said. You don't even understand the 90% bits. You say its a problem, its only a problem if nearly all do it. Hence 90%. I'll simplify.

If 5% of the volume from sellers and exchanges decide to block any non clean BTC coins, what does happen?

That business will be brought to the rest of 95%.

If 40% of the volume from sellers and exchanges decide to block any non clean BTC coins, what does happen?

That business will be brought to the rest of 60%

And thats goes on and on, until about 90%.

If that didn't explain clearly enough, i'll explain that too;

As long as people can go somewhere and get full value with their coins, the other portion that does not value those coins at the exchange rate will just be walked around. Its not a complicated concept.

TLDR: Fungibility is not a concept relevant to BTC.

Conclusion: Everything you say is based on a Fallacy.

Keep telling yourself that.

Just because you say something does not make it true.

Let's agree to disagree.

Well we can do that, but i'm not saying i agree or do not agree. I'm saying you're raising alarm about a fire where there is none. I'm just stating empirical facts;

Are exchanges over or devaluating certain Bitcoins depending on their history?

The answer is simply no. Therefore you are wrong, no matter what i think.

But i can agree to stop arguing. We both made our points clear and others who read this are welcome to make their own opinions, since i think from both aisle, all that was said should give all the needed information.

[BoscoMurray]

Are we discussing the fact that Bitcoin is not perfectly fungible, or how big an issue a lack of fungibility is?

Adam Back considers that Bitcoin is not perfectly fungible when he says:

some of the analysis you talked about could potentially lead to some currency units which you might receive for no fault of your own being somewhat tainted or frowned upon or, you know, so things are generally okay at the moment and the fact of it's been treated as fungible, but there is a slight risk that could degrade at some point.

Here's the full transcript of an interview with him about Confidential Transactions: https://www.weusecoins.com/adam-back-confidential-transactions/

Having read this thread I am actually coming around to the idea that fungibility is not as big a problem as I'd thought before.

I think the point some are trying to make is that since people (peers or third-parties) could trace historical movements of bitcoins, they could refuse them based on this history. It is a possibility, that's all. Whether in a world where Bitcoin exists alongside FIAT or not, it is still possible.


More Adam Back:

I mean, it increases indirectly so it doesn't directly -- I mean, so what bitcoin does have is a way to improve fungibility somewhat is the idea that the addresses are not reused.  So, you know, when you make a payment and it split into a payment and change address the some ambiguity as to which was the payment and which was the change.  And as that flows through the system and, you know, there are thousands of transactions in a big graphic it becomes increasingly not ambiguous as to, you know, it was --

So there are ways to improve fungibility, therefore it cannot be perfect in its current state. Regardless of how uneconomically viable you may think it is to exploit this imperfection, it is impossible to know how and who will exploit this in the future. Businesses might not survive by following such practices, but is it so impossible to imagine that government probably would exploit if it gives them greater control of people or trade? I'd say that's a distinct possibility, and this is my biggest worry.

Surely the best solution is perfect privacy (unlinkable, untraceable transactions), providing perfect fungibility. The best of both worlds. Why compromise?

[smoothie]

My main concern is people saying that bitcoins imperfect fungibility is not and could not be a problem at any magnitude.

Outright saying fungibility does not apply to Bitcoin is pure ignorance of the facts.

[brg444]

Are we discussing the fact that Bitcoin is not perfectly fungible, or how big an issue a lack of fungibility is?

Adam Back considers that Bitcoin is not perfectly fungible when he says:

some of the analysis you talked about could potentially lead to some currency units which you might receive for no fault of your own being somewhat tainted or frowned upon or, you know, so things are generally okay at the moment and the fact of it's been treated as fungible, but there is a slight risk that could degrade at some point.

Here's the full transcript of an interview with him about Confidential Transactions: https://www.weusecoins.com/adam-back-confidential-transactions/

Having read this thread I am actually coming around to the idea that fungibility is not as big a problem as I'd thought before.

I think the point some are trying to make is that since people (peers or third-parties) could trace historical movements of bitcoins, they could refuse them based on this history. It is a possibility, that's all. Whether in a world where Bitcoin exists alongside FIAT or not, it is still possible.


More Adam Back:

I mean, it increases indirectly so it doesn't directly -- I mean, so what bitcoin does have is a way to improve fungibility somewhat is the idea that the addresses are not reused.  So, you know, when you make a payment and it split into a payment and change address the some ambiguity as to which was the payment and which was the change.  And as that flows through the system and, you know, there are thousands of transactions in a big graphic it becomes increasingly not ambiguous as to, you know, it was --

So there are ways to improve fungibility, therefore it cannot be perfect in its current state. Regardless of how uneconomically viable you may think it is to exploit this imperfection, it is impossible to know how and who will exploit this in the future. Businesses might not survive by following such practices, but is it so impossible to imagine that government probably would exploit if it gives them greater control of people or trade? I'd say that's a distinct possibility, and this is my biggest worry.

Surely the best solution is perfect privacy (unlinkable, untraceable transactions), providing perfect fungibility. The best of both worlds. Why compromise?

The problem is that people have a mostly incorrect interpretation of what fungibility is.

Until they come to accept that fungibility is a property inherent to a system and is not dependent on arbitrary decisions made by its users then they will never realize that what they are in fact discussing is an issue with Bitcoin's privacy/transparency

[brg444]

My main concern is people saying that bitcoins imperfect fungibility is not and could not be a problem at any magnitude.

Outright saying fungibility does not apply to Bitcoin is pure ignorance of the facts.

Your complains are all about Bitcoin's privacy.

Bitcoin is perfectly fungible. The simple and undebatable observation that every single satoshis are perfectly indistinguishable & capable of mutual substitution are proof enough of this.

[VirosaGITS]

Are we discussing the fact that Bitcoin is not perfectly fungible, or how big an issue a lack of fungibility is?

Personally, i'm saying the concept of grading a currency's fungibility is fine, but its not a problem or even really applicable for Bitcoin, since fungibility not meant to apply to a transaction history.

Its possible to argue semantics, but the fact remain that it is not an issue and as long as there are exchanges who take any for the full price, it does not matter if some does not.

And since those exchanges thrives on the value of bitcoin and getting the most traffic possible, refusing certain BTC based on transaction history is simply not going to happen.

TLDR: Fungibility does not apply to a currency,s transaction history, ledger. That BTC has a public ledger does not change that fact. You can start cherrypicking but the clerk at the market you're buying stuff from really does not give a damn about the Bill,s transaction history, but it could be asked, just as it could be checked for BTC.

BTC is not any different, its just transparent.

My main concern is people saying that bitcoins imperfect fungibility is not and could not be a problem at any magnitude.

Outright saying fungibility does not apply to Bitcoin is pure ignorance of the facts.

Thats because fungibility cause a problem for normal currency, but it does not for Bitcoin. Its like a different universe with different laws of physics. Its facts, not ignorance.

[brg444]

Are we discussing the fact that Bitcoin is not perfectly fungible, or how big an issue a lack of fungibility is?

Personally, i'm saying the concept of grading a currency's fungibility is fine, but its not a problem or even really applicable for Bitcoin, since fungibility not meant to apply to a transaction history.

Its possible to argue semantics, but the fact remain that it is not an issue and as long as there are exchanges who take any for the full price, it does not matter if some does not.

And since those exchanges thrives on the value of bitcoin and getting the most traffic possible, refusing certain BTC based on transaction history is simply not going to happen.

TLDR: Fungibility does not apply to a currency,s transaction history, ledger. That BTC has a public ledger does not change that fact. You can start cherrypicking but the clerk at the market you're buying stuff from really does not give a damn about the Bill,s transaction history, but it could be asked, just as it could be checked for BTC.

BTC is not any different, its just transparent.

My main concern is people saying that bitcoins imperfect fungibility is not and could not be a problem at any magnitude.

Outright saying fungibility does not apply to Bitcoin is pure ignorance of the facts.

Thats because fungibility cause a problem for normal currency, but it does not for Bitcoin. Its like a different universe with different laws of physics. Its facts, not ignorance.

Exactly.

Bitcoin is a ledger and if you consider that all units within a ledger are equal then Bitcoin is perfectly fungible, no matter the movement history of its units.

[smoothie]

Are we discussing the fact that Bitcoin is not perfectly fungible, or how big an issue a lack of fungibility is?

Personally, i'm saying the concept of grading a currency's fungibility is fine, but its not a problem or even really applicable for Bitcoin, since fungibility not meant to apply to a transaction history.

Its possible to argue semantics, but the fact remain that it is not an issue and as long as there are exchanges who take any for the full price, it does not matter if some does not.

And since those exchanges thrives on the value of bitcoin and getting the most traffic possible, refusing certain BTC based on transaction history is simply not going to happen.

TLDR: Fungibility does not apply to a currency,s transaction history, ledger. That BTC has a public ledger does not change that fact. You can start cherrypicking but the clerk at the market you're buying stuff from really does not give a damn about the Bill,s transaction history, but it could be asked, just as it could be checked for BTC.

BTC is not any different, its just transparent.

My main concern is people saying that bitcoins imperfect fungibility is not and could not be a problem at any magnitude.

Outright saying fungibility does not apply to Bitcoin is pure ignorance of the facts.

Thats because fungibility cause a problem for normal currency, but it does not for Bitcoin. Its like a different universe with different laws of physics. Its facts, not ignorance.

Your own analogy of bills dated or marked with perfume was debunked by me showing a clear difference in the enforceability of acceptance of denial of physical cash vs Bitcoin.

You never retorted but rather ignored the glaring problem with your analogy.

Go back and read your own post.

[VirosaGITS]

Are we discussing the fact that Bitcoin is not perfectly fungible, or how big an issue a lack of fungibility is?

Personally, i'm saying the concept of grading a currency's fungibility is fine, but its not a problem or even really applicable for Bitcoin, since fungibility not meant to apply to a transaction history.

Its possible to argue semantics, but the fact remain that it is not an issue and as long as there are exchanges who take any for the full price, it does not matter if some does not.

And since those exchanges thrives on the value of bitcoin and getting the most traffic possible, refusing certain BTC based on transaction history is simply not going to happen.

TLDR: Fungibility does not apply to a currency,s transaction history, ledger. That BTC has a public ledger does not change that fact. You can start cherrypicking but the clerk at the market you're buying stuff from really does not give a damn about the Bill,s transaction history, but it could be asked, just as it could be checked for BTC.

BTC is not any different, its just transparent.

My main concern is people saying that bitcoins imperfect fungibility is not and could not be a problem at any magnitude.

Outright saying fungibility does not apply to Bitcoin is pure ignorance of the facts.

Thats because fungibility cause a problem for normal currency, but it does not for Bitcoin. Its like a different universe with different laws of physics. Its facts, not ignorance.

Your own analogy of bills dated or marked with perfume was debunked by me showing a clear difference in the enforceability of acceptance of denial of physical cash vs Bitcoin.

You never retorted but rather ignored the glaring problem with your analogy.

Go back and read your own post.

Its because you aim on a specific word or sentence and ignore what the analogy its trying to explain. Its like a angry bull that is seeing red;

I'm saying, the transaction history of Bills but even more so the transaction history of FIAT which most of it is done Online is the same as Bitcoin. The transaction history is there, its available, just not publicly.

Yet FIAT is still finely fungible and in that aspect, BTC is just as well, the difference is that BTC's ledger is publicly available, for transparency. That does not change anything.

Everyone is able to discriminate either way, it just does not matter if they do.

So for FIAT and for BTC, fungibility is not a problem.

[brg444]

Here is a transaction:

https://blockchain.info/tx/a7f71be180e6180c48c1631009999a79a117947f00912beb466c594bd7eba3ad

Unless you can demonstrate to me exactly which satoshis from outputs A,B,C went into input D,E then our discussion here is done.

That is what fungibility means.

Yes I know you can identify and track the outputs history yet it is certain you cannot differentiate the units in each of them.

This is what fungibility is.

[BoscoMurray]

I think I can understand all of the points being made now, and my preference is that nobody has any way to discriminate against a satoshi based purely on it's previous transaction history. Whether this is fungibility or not (I can see why it is perceived to be), this is all I desire

[onemorexmr]

I think I can understand all of the points being made now, and my preference is that nobody has anyway to discriminate against a satoshi based purely on it's previous transaction history. Whether this is fungibility or not (I can see why it is perceived to be), this is all I desire

please tell that companies like coinbase... they do that already.
but i guess no one cares because it only matters if you want to sell bitcoins...and those people seem to be bad anyway ;-)

[VirosaGITS]

Here is a transaction:

https://blockchain.info/tx/a7f71be180e6180c48c1631009999a79a117947f00912beb466c594bd7eba3ad

Unless you can demonstrate to me exactly which satoshis from outputs A,B,C went into input D,E then our discussion here is done.

That is what fungibility means.

Yes I know you can identify and track the outputs history yet it is certain you cannot differentiate the units in each of them.

This is what fungibility is.

It was said that, the second any of these satoshi is connected to a dirty satoshi, since its not possible to discriminate individually, then all sats from that transaction are dirty. And i said that is ridiculous and discriminating as such is just doing so for the sake of the arguments.

Its ridiculous but that seem to be what is being said and that however is something i directly do not agree with.

[brg444]

I think I can understand all of the points being made now, and my preference is that nobody has any way to discriminate against a satoshi based purely on it's previous transaction history. Whether this is fungibility or not (I can see why it is perceived to be), this is all I desire

Coming soon to a sidechain near you.

[BoscoMurray]

I think I can understand all of the points being made now, and my preference is that nobody has any way to discriminate against a satoshi based purely on it's previous transaction history. Whether this is fungibility or not (I can see why it is perceived to be), this is all I desire

Coming soon to a sidechain near you.

I should have said: I'd like it in Bitcoin, not in a side chain

[brg444]

I think I can understand all of the points being made now, and my preference is that nobody has any way to discriminate against a satoshi based purely on it's previous transaction history. Whether this is fungibility or not (I can see why it is perceived to be), this is all I desire

Coming soon to a sidechain near you.

I should have said: I'd like it in Bitcoin, not in a side chain

Bitcoin has it is constructed requires a transparent ledger. Such a ledger also has its perks.

Do you appreciate what a sidechain is and how it helps resolves issues with Bitcoin's limited extensibility and functions?

[smoothie]

Are we discussing the fact that Bitcoin is not perfectly fungible, or how big an issue a lack of fungibility is?

Personally, i'm saying the concept of grading a currency's fungibility is fine, but its not a problem or even really applicable for Bitcoin, since fungibility not meant to apply to a transaction history.

Its possible to argue semantics, but the fact remain that it is not an issue and as long as there are exchanges who take any for the full price, it does not matter if some does not.

And since those exchanges thrives on the value of bitcoin and getting the most traffic possible, refusing certain BTC based on transaction history is simply not going to happen.

TLDR: Fungibility does not apply to a currency,s transaction history, ledger. That BTC has a public ledger does not change that fact. You can start cherrypicking but the clerk at the market you're buying stuff from really does not give a damn about the Bill,s transaction history, but it could be asked, just as it could be checked for BTC.

BTC is not any different, its just transparent.

My main concern is people saying that bitcoins imperfect fungibility is not and could not be a problem at any magnitude.

Outright saying fungibility does not apply to Bitcoin is pure ignorance of the facts.

Thats because fungibility cause a problem for normal currency, but it does not for Bitcoin. Its like a different universe with different laws of physics. Its facts, not ignorance.

Your own analogy of bills dated or marked with perfume was debunked by me showing a clear difference in the enforceability of acceptance of denial of physical cash vs Bitcoin.

You never retorted but rather ignored the glaring problem with your analogy.

Go back and read your own post.

Its because you aim on a specific word or sentence and ignore what the analogy its trying to explain. Its like a angry bull that is seeing red;

I'm saying, the transaction history of Bills but even more so the transaction history of FIAT which most of it is done Online is the same as Bitcoin. The transaction history is there, its available, just not publicly.

Yet FIAT is still finely fungible and in that aspect, BTC is just as well, the difference is that BTC's ledger is publicly available, for transparency. That does not change anything.

Everyone is able to discriminate either way, it just does not matter if they do.

So for FIAT and for BTC, fungibility is not a problem.

Fiat gets its fungibility from governments.

Hard to compare the two really.

You originally made an analogy and all I can do is take that analogy and run with it. If you had something else to say in a more elegant way you should have said that instead of your broken analogy that fell apart just on the enforceability topic between the two (bitcoin and fiat "blacklisting").

It isn't my fault that you gave such a bad analogy that didn't hold up when you really put it into practice from a regulatory stand point.

Yeah it doesn't matter right now but it definitely can matter in the future. I've never said it is a huge problem right now, but only that it can be a big problem in the future if things don't go in the direction you are bias to.

Neither of us know the future (as we are in uncharted waters with bitcoin) but I do know that there is a possibility for fungibility (or distinguishability) to be a hot topic of discussion and potentially a problem with bitcoin's usage (given the legacy banking system is still around).

Transparency of the ledger does change something...the ability to discriminate. You can't discriminate with using fiat as it is government decreed to be accepted for payment of debts public and private as well as payment for goods and services that is the medium of exchange. That is the difference.

[smoothie]

Here is a transaction:

https://blockchain.info/tx/a7f71be180e6180c48c1631009999a79a117947f00912beb466c594bd7eba3ad

Unless you can demonstrate to me exactly which satoshis from outputs A,B,C went into input D,E then our discussion here is done.

That is what fungibility means.

Yes I know you can identify and track the outputs history yet it is certain you cannot differentiate the units in each of them.

This is what fungibility is.

It was said that, the second any of these satoshi is connected to a dirty satoshi, since its not possible to discriminate individually, then all sats from that transaction are dirty. And i said that is ridiculous and discriminating as such is just doing so for the sake of the arguments.

Its ridiculous but that seem to be what is being said and that however is something i directly do not agree with.

it appears to be a difference of what you define fungibility is to you brg444 and how I choose to define it to me.

To each his own.

[VirosaGITS]

Here is a transaction:

https://blockchain.info/tx/a7f71be180e6180c48c1631009999a79a117947f00912beb466c594bd7eba3ad

Unless you can demonstrate to me exactly which satoshis from outputs A,B,C went into input D,E then our discussion here is done.

That is what fungibility means.

Yes I know you can identify and track the outputs history yet it is certain you cannot differentiate the units in each of them.

This is what fungibility is.

It was said that, the second any of these satoshi is connected to a dirty satoshi, since its not possible to discriminate individually, then all sats from that transaction are dirty. And i said that is ridiculous and discriminating as such is just doing so for the sake of the arguments.

Its ridiculous but that seem to be what is being said and that however is something i directly do not agree with.

it appears to be a difference of what you define fungibility is to you brg444 and how I choose to define it to me.

To each his own.

I'm trying to say that the issues non-fungibility would cause in previous currency does not apply to Bitcoin. What i call it, what you call it, it does not matter. If it does not cause any problem, then it does not cause any issues. Its quite simple.

Since whether it is fungible or not become irrelevant. Whether we agree or not on if BTC is fungible or not, also become irrelevant.

We can discuss it for academic reasons, but saying it create problem in practice is a bit silly.

[BoscoMurray]

I think I can understand all of the points being made now, and my preference is that nobody has any way to discriminate against a satoshi based purely on it's previous transaction history. Whether this is fungibility or not (I can see why it is perceived to be), this is all I desire

Coming soon to a sidechain near you.

I should have said: I'd like it in Bitcoin, not in a side chain

Bitcoin has it is constructed requires a transparent ledger. Such a ledger also has its perks.

Do you appreciate what a sidechain is and how it helps resolves issues with Bitcoin's limited extensibility and functions?

I think I do. I'd like to see privacy as the default, and there can be a transparent side chain. Privacy should be of utmost importance. I imagine more transactions would benefit from privacy, and less of them from transparency.