<p>Because a transactions with 5 inputs and 5 outputs is possible and it doesn't make sense to ask the question &quot;the output to me comes from which input?&quot;</p>
<p>Simply, transactions are about total input value and total output value and the rest is miner fees. Tracking a coin's origin is not technically possible.</p>

CC BY-SA 4.0
2021-03-03T08:49:34.507Z
2021-03-03T08:49:34.507Z
MCCCS
<p>I remember news about some exchange actually banning users based on some kind of &quot;reputation score&quot; on the inputs/coin parts they controlled/used, or got Bitcoin sent to them from. So even years and years back, they had this mapped out somehow.</p>
<p>Why can't they do the same today? Aren't they? If not, why? Why do they not take this obvious path to harassing and restricting people to only use Bitcoin in &quot;approved&quot; ways with &quot;approved&quot; people/entities?</p>
<p>Did they stop doing it for some reason? What stops them from doing this and thus locking out tons of people who have &quot;dealt with undesirables&quot;?</p>

CC BY-SA 4.0
2021-03-03T11:38:09.863Z
See [this answer](https://bitcoin.stackexchange.com/a/102242/13866) to a different question for an example of what MCCCS has explained below.
RedGrittyBrick
<transactions><security><privacy><censorship-resistance>
What would stop some major company from blacklisting specific Bitcoins based on the "inputs" used and their "origins"?
Ryden C.
# What would stop some major company from blacklisting specific Bitcoins based on the "inputs" used and their "origins"?

(Asked by: username_0 on 2021-03-03)

I remember news about some exchange actually banning users based on some kind of "reputation score" on the inputs/coin parts they controlled/used, or got Bitcoin sent to them from. So even years and years back, they had this mapped out somehow.

Why can't they do the same today? Aren't they? If not, why? Why do they not take this obvious path to harassing and restricting people to only use Bitcoin in "approved" ways with "approved" people/entities?

Did they stop doing it for some reason? What stops them from doing this and thus locking out tons of people who have "dealt with undesirables"?

**Tags:** transactions, security, privacy, censorship-resistance

> **Comments:**
> **username_1**: See [this answer](https://bitcoin.stackexchange.com/a/102242/13866) to a different question for an example of what username_2 has explained below.  

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## 1 answers

### Answer by username_2 on 2021-03-03. Score: 2

Because a transactions with 5 inputs and 5 outputs is possible and it doesn't make sense to ask the question "the output to me comes from which input?"

Simply, transactions are about total input value and total output value and the rest is miner fees. Tracking a coin's origin is not technically possible.


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